CVE-2018-1303

HIGHNVD 7.58.6
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score elevated to 8.6 because EPSS predicted 70% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs) when EchelonGraph scored this CVE. NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this weekElevated
8.6EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • 587 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
  • High exploitation likelihood — EPSS 70%
CISA-KEV: Not listedEPSS PROB: 70%CVSS: 7.5Exploit: No code on recordExposed services: 587

A fix is available — apply it.

A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 due to an out of bound read while preparing data to be cached in shared memory. It could be used as a Denial of Service attack against users of mod_cache_socache. The vulnerability is considered as low risk since mod_cache_socache is not widely used, mod_cache_disk is not concerned by this vulnerability.

Internet exposure · derived from Shodan data

587 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2018-1303, in our KEV-Exposure radar’s Shodan-derived sample.

across 64 countries (United States, Germany, Poland, Netherlands, Japan)top: http_server
See the KEV-Exposure radar →Derived from Shodan data. Shodan data is owned by Shodan, which holds its copyright (© Shodan). EchelonGraph claims no ownership of it or copyright in it. Aggregate, host-redacted.

How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.

CVSS v3
7.5
EG Score
8.6HIGHhigh confidence
EG Risk
62
EG Risk 62/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation70% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
70%
EPSS %ILE
99th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.6): severity, escalated by confirmed exploitation. This CVE's 8.6 is EPSS's lift toward 9.0 from its impact severity (EG Severity, CVSS 7.5 HIGH): a likelihood of exploitation, not impact.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
70% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-21). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

March 26, 2018

Last Modified

November 21, 2024

References (25)

15 of 25 shown · show the other 10

Vendor Advisories for CVE-2018-1303(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibapache2-mod-proxy-html (1:2.4.7-1ubuntu4.20) @ trusty2026-10-21ubuntu
ubuntuapache2-utils (2.4.29-1ubuntu4.1) @ bionic2026-10-21ubuntu
redhathttpd-0:2.4.6-95.el72020-09-29redhat
redhatjbcs-httpd24-openssl-1:1.0.2n-14.jbcs.el72019-02-18redhat
redhathttpd2019-02-18redhat
redhathttpd24-nghttp2-0:1.7.1-7.el72018-11-13redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(27 across 27 ecosystems)
Alpine:v3.10(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.11(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.12(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.4(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.5(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.6(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.7(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.8(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Alpine:v3.9(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-r0: fixed in 2.4.33-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-1: fixed in 2.4.33-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-1: fixed in 2.4.33-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-1: fixed in 2.4.33-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.4.33-1: fixed in 2.4.33-1
—
Debian:8(1)
PackageVulnerable rangeFix by version rangeDependents
apache22.4.10-10 ... 2.4.10-10+deb8u9 (12 versions)
  • every version up to 2.4.10-10+deb8u12: fixed in 2.4.10-10+deb8u12
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
apache22.4.25-3, 2.4.25-3+deb9u1, 2.4.25-3+deb9u2, 2.4.25-3+deb9u3
  • every version up to 2.4.25-3+deb9u4: fixed in 2.4.25-3+deb9u4
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 8× in last 7d / 25× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 84 of 123 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 16 repeat rows among the latest 100 are merged into the row they repeat. The 39 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-23 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  2. 2026-10-21 22:33 UTCEG score recompute
  3. 2026-10-21 22:33 UTCVendor advisory
  4. 2026-10-21 22:33 UTCGHSA enrichmentGHSA-8rrj-w45x-2fr2 · GitHub severity HIGH · GitHub CVSS 7.5
  5. 2026-10-21 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  6. 2026-10-20 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  7. 2026-10-18 10:21 UTCEG score recompute
  8. 2026-10-17 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  9. 2026-10-15 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  10. 2026-10-14 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  11. 2026-10-13 16:27 UTCEPSS rescoreEPSS 70% · 99th percentile
  12. 2026-10-12 20:19 UTCEG score recompute
  13. 2026-10-12 16:28 UTCEPSS rescoreEPSS 70% · 99th percentile
  14. 2026-10-12 00:42 UTCEG score recompute
  15. 2026-10-10 19:55 UTCEPSS rescoreEPSS 70% · 99th percentile
  16. 2026-10-08 16:36 UTCEPSS rescoreEPSS 70% · 99th percentile
  17. 2026-10-07 23:42 UTCEPSS rescoreEPSS 70% · 99th percentile
  18. 2026-10-06 15:12 UTCEPSS rescoreEPSS 70% · 99th percentile
  19. 2026-10-03 14:21 UTCEPSS rescoreEPSS 70% · 99th percentile
  20. 2026-10-01 19:44 UTCEPSS rescoreEPSS 70% · 99th percentile
  21. 2026-09-30 09:53 UTCEG score recompute
  22. 2026-09-29 07:45 UTCOSV refresh
  23. 2026-09-27 13:40 UTCEPSS rescoreEPSS 70% · 99th percentile
  24. 2026-09-26 15:53 UTCEPSS rescoreEPSS 70% · 99th percentile
  25. 2026-09-24 13:59 UTCEPSS rescoreEPSS 70% · 99th percentile
Show 59 more
  1. 2026-09-19 15:36 UTCEPSS rescoreEPSS 70% · 99th percentile
  2. 2026-09-18 19:22 UTCEPSS rescoreEPSS 70% · 99th percentile
  3. 2026-09-17 19:22 UTCEPSS rescoreEPSS 70% · 99th percentile
  4. 2026-09-16 05:06 UTCEPSS rescoreEPSS 70% · 99th percentile
  5. 2026-09-13 16:42 UTCEPSS rescoreEPSS 70% · 99th percentile
  6. 2026-09-12 14:56 UTCEPSS rescoreEPSS 70% · 99th percentile
  7. 2026-09-11 14:47 UTCEPSS rescoreEPSS 70% · 99th percentile
  8. 2026-09-11 09:32 UTCEPSS rescoreEPSS 70% · 99th percentile
  9. 2026-09-09 13:53 UTCOSV refresh
  10. 2026-09-06 13:43 UTCEPSS rescoreEPSS 70% · 99th percentile
  11. 2026-09-05 15:24 UTCEPSS rescoreEPSS 65% · 99th percentile
  12. 2026-09-04 13:56 UTCEPSS rescoreEPSS 70% · 99th percentile
  13. 2026-09-02 14:07 UTCEPSS rescoreEPSS 70% · 99th percentile
  14. 2026-09-01 13:49 UTCEPSS rescoreEPSS 70% · 99th percentile
  15. 2026-08-28 21:36 UTCEPSS rescoreEPSS 65% · 99th percentile
  16. 2026-08-27 14:21 UTCEPSS rescoreEPSS 70% · 99th percentile
  17. 2026-08-26 14:42 UTCEPSS rescoreEPSS 70% · 99th percentile
  18. 2026-08-22 20:37 UTCOSV refresh
  19. 2026-08-21 23:45 UTCEPSS rescoreEPSS 70% · 99th percentile
  20. 2026-08-20 22:51 UTCEPSS rescoreEPSS 70% · 99th percentile
  21. 2026-08-19 17:00 UTCEPSS rescoreEPSS 70% · 99th percentile
  22. 2026-08-17 13:43 UTCEPSS rescoreEPSS 70% · 99th percentile
  23. 2026-08-16 02:10 UTCEPSS rescoreEPSS 70% · 99th percentile
  24. 2026-08-15 01:26 UTCEPSS rescoreEPSS 70% · 99th percentile
  25. 2026-08-13 21:56 UTCEPSS rescoreEPSS 70% · 99th percentile
  26. 2026-08-12 13:46 UTCEPSS rescoreEPSS 70% · 99th percentile
  27. 2026-08-09 13:43 UTCEPSS rescoreEPSS 70% · 99th percentile
  28. 2026-08-07 16:23 UTCEPSS rescoreEPSS 70% · 99th percentile
  29. 2026-08-07 00:20 UTCOSV refresh
  30. 2026-08-06 13:42 UTCEPSS rescoreEPSS 70% · 99th percentile
  31. 2026-08-05 19:13 UTCEPSS rescoreEPSS 70% · 99th percentile
  32. 2026-08-04 15:05 UTCEPSS rescoreEPSS 70% · 99th percentile
  33. 2026-07-30 16:24 UTCEPSS rescoreEPSS 71% · 99th percentile
  34. 2026-07-28 15:32 UTCEPSS rescoreEPSS 71% · 99th percentile
  35. 2026-07-26 14:51 UTCEPSS rescoreEPSS 71% · 99th percentile
  36. 2026-07-25 14:14 UTCEPSS rescoreEPSS 71% · 99th percentile
  37. 2026-07-24 14:14 UTCEPSS rescoreEPSS 71% · 99th percentile
  38. 2026-07-23 01:33 UTCEG score recompute▲ 1.10
  39. 2026-07-22 22:13 UTCEG score recompute
  40. 2026-07-22 14:05 UTCEPSS rescoreEPSS 71% · 99th percentile
  41. 2026-07-21 15:48 UTCOSV refresh
  42. 2026-07-20 17:04 UTCEPSS rescoreEPSS 71% · 99th percentile
  43. 2026-07-19 14:28 UTCEPSS rescoreEPSS 71% · 99th percentile
  44. 2026-07-16 16:59 UTCEPSS rescoreEPSS 71% · 99th percentile
  45. 2026-07-15 16:55 UTCEPSS rescoreEPSS 71% · 99th percentile
  46. 2026-07-15 01:56 UTCEPSS rescoreEPSS 71% · 99th percentile
  47. 2026-07-13 06:10 UTCEPSS rescoreEPSS 71% · 99th percentile
  48. 2026-07-11 08:24 UTCEPSS rescoreEPSS 71% · 99th percentile
  49. 2026-07-09 19:06 UTCEPSS rescoreEPSS 71% · 99th percentile
  50. 2026-07-07 13:42 UTCEPSS rescoreEPSS 71% · 99th percentile
  51. 2026-07-04 11:26 UTCOSV refresh
  52. 2026-07-04 06:28 UTCEPSS rescoreEPSS 71% · 99th percentile
  53. 2026-07-02 16:54 UTCEPSS rescoreEPSS 71% · 99th percentile
  54. 2026-07-01 15:03 UTCEPSS rescoreEPSS 71% · 99th percentile
  55. 2026-06-28 04:53 UTCEPSS rescoreEPSS 71% · 99th percentile
  56. 2026-06-27 03:06 UTCEPSS rescoreEPSS 71% · 99th percentile
  57. 2026-06-25 13:47 UTCEPSS rescoreEPSS 71% · 99th percentile
  58. 2026-06-24 14:02 UTCEPSS rescoreEPSS 71% · 99th percentile
  59. 2026-06-23 21:30 UTCEPSS rescoreEPSS 71% · 99th percentile

Frequently asked(5)

What is CVE-2018-1303?
CVE-2018-1303 is a high-severity vulnerability; its CVE record was published on March 26, 2018. A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 due to an out of bound read while preparing data to be cached in shared memory. It could be used as a Denial of Service attack against users of modcachesocache. The vulnerability is considered…
When was CVE-2018-1303 made public?
CVE-2018-1303 was made public on March 23, 2018: that is the date its CVE record's CNA, Apache Software Foundation, gives for when the vulnerability was made public. The CVE record itself was published on March 26, 2018. EchelonGraph's copy of the record carries a last-modified date of November 21, 2024; the record at its source may have been updated since.
Is CVE-2018-1303 actively exploited?
CVE-2018-1303 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 70% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2018-1303?
CVE-2018-1303 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.6 (HIGH).
How do I remediate CVE-2018-1303?
A fix for CVE-2018-1303 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2018-1303 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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