CVE-2018-11784

CRITICALNVD 4.39.0
EchelonGraph scoreHIGH confidence

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

Score elevated to 9.0 because EPSS predicted 98% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs) when EchelonGraph scored this CVE. NVD baseline CVSS 4.3 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this weekElevated
9.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • 104 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 98%
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 98%CVSS: 4.3Exploit: Public PoCExposed services: 104

A fix is available — apply it.

When the default servlet in Apache Tomcat versions 9.0.0.M1 to 9.0.11, 8.5.0 to 8.5.33 and 7.0.23 to 7.0.90 returned a redirect to a directory (e.g. redirecting to '/foo/' when the user requested '/foo') a specially crafted URL could be used to cause the redirect to be generated to any URI of the attackers choice.

Internet exposure · derived from Shodan data

104 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2018-11784, in our KEV-Exposure radar’s Shodan-derived sample.

across 25 countries (China, United States, Korea, Republic of, France, Germany)top: tomcat
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
4.3
EG Score
9.0CRITICALhigh confidence
EG Risk
58
EG Risk 58/100

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)
Severity43% × 45%
Impact severity (EG Severity): CVSS 4.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation98% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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
98%
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 (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is EPSS's lift toward 9.0 from its impact severity (EG Severity, CVSS 4.3 MEDIUM): a likelihood of exploitation, not impact.

EG Severity
4.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
98% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-22). 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 every mission impact level.CISA BOD 26-04: 60 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 every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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)60 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 Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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

October 4, 2018

Last Modified

October 15, 2026

Advisory Details (6)

Auto-updated Oct 14, 2026
Patch available. Sources: redhat.
Web page

Pony Mail

https://lists.apache.org/thread.html/1dd0a59c1295cc08ce4c9e7edae5ad2268acc9ba55adcefa0532e5ba%40%3Cdev.tomcat.apache.org%3E
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2019:0485
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2019:0131
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2019:0130
Web page

CVE-2018-11784 - PSIRT.COM

http://www.securityfocus.com/bid/105524
Web page

Packet Storm

http://packetstormsecurity.com/files/163456/Apache-Tomcat-9.0.0M1-Open-Redirect.html

Patch Availability(7)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntutomcat8-user (8.0.32-1ubuntu1.8) @ xenial2026-10-23ubuntu
redhatpki-deps:10.6-8000020190524054914.55190bc52019-06-18redhat
redhattomcat-0:7.0.76-9.el7_62019-03-13redhat
redhattomcat2019-01-22redhat
redhattomcat-native-0:1.2.17-18.redhat_18.ep7.el72019-01-22redhat
redhatjws5-tomcat-0:9.0.7-12.redhat_12.1.el7jws2018-10-03redhat
redhatpatch2018-10-03redhat

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

(4 across 3 ecosystems)
Debian:8(2)
PackageVulnerable rangeFix by version rangeDependents
tomcat77.0.56-3 ... 7.0.56-3+really7.0.90-1 (15 versions)
  • every version up to 7.0.56-3+really7.0.91-1: fixed in 7.0.56-3+really7.0.91-1
—
tomcat88.0.14-1 ... 8.0.14-1+deb8u9 (14 versions)
  • every version up to 8.0.14-1+deb8u14: fixed in 8.0.14-1+deb8u14
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat88.5.14-1 ... 8.5.39-1 (36 versions)
  • every version up to 8.5.50-0+deb9u1: fixed in 8.5.50-0+deb9u1
—
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.apache.tomcat.embed:tomcat-embed-core9.0.1 ... 9.0.8 (9 versions)
  • 8.5.0 up to 8.5.34: fixed in 8.5.34
  • 7.0.23 up to 7.0.91: fixed in 7.0.91
  • 9.0.0 up to 9.0.12: fixed in 9.0.12
—

Weakness Classification(1)

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

All Vendor Advisories

(7)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 18× in last 7d / 35× 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.

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. 12 repeat rows among the latest 97 are merged into the row they repeat.

  1. 2026-10-23 00:26 UTCEG score recompute
  2. 2026-10-23 00:26 UTCVendor advisory
  3. 2026-10-22 00:12 UTCEG score recompute
  4. 2026-10-22 00:12 UTCVendor advisory
  5. 2026-10-21 00:00 UTCEG score recompute
  6. 2026-10-21 00:00 UTCVendor advisory
  7. 2026-10-20 16:27 UTCEPSS rescoreEPSS 98% · 99th percentile
  8. 2026-10-19 23:48 UTCEG score recompute
  9. 2026-10-19 23:48 UTCVendor advisory
  10. 2026-10-19 16:27 UTCEPSS rescoreEPSS 98% · 99th percentile
  11. 2026-10-18 23:12 UTCEG score recompute
  12. 2026-10-18 23:12 UTCVendor advisory
  13. 2026-10-18 10:22 UTCEG score recompute
  14. 2026-10-17 22:13 UTCEG score recompute
  15. 2026-10-17 22:13 UTCVendor advisory
  16. 2026-10-17 16:27 UTCEPSS rescoreEPSS 98% · 99th percentile
  17. 2026-10-16 22:01 UTCEG score recompute
  18. 2026-10-16 22:01 UTCVendor advisory
  19. 2026-10-15 18:28 UTCVendor advisory
  20. 2026-10-15 17:34 UTCEG score recompute
  21. 2026-10-15 17:34 UTCVendor advisory
  22. 2026-10-15 11:44 UTCEG score recompute
  23. 2026-10-15 11:44 UTCVendor advisory
  24. 2026-10-14 07:14 UTCEG score recompute
  25. 2026-10-14 07:14 UTCVendor advisory
Show 60 more
  1. 2026-10-13 02:30 UTCVendor advisory
  2. 2026-10-12 20:20 UTCEG score recompute
  3. 2026-10-12 00:43 UTCEG score recompute
  4. 2026-10-11 13:41 UTCEPSS rescoreEPSS 98% · 99th percentile
  5. 2026-10-10 19:55 UTCEPSS rescoreEPSS 98% · 99th percentile
  6. 2026-10-07 23:41 UTCEPSS rescoreEPSS 98% · 99th percentile
  7. 2026-09-30 20:40 UTCOSV refresh
  8. 2026-09-30 09:52 UTCEG score recompute
  9. 2026-09-26 15:53 UTCEPSS rescoreEPSS 98% · 99th percentile
  10. 2026-09-24 13:59 UTCEPSS rescoreEPSS 98% · 99th percentile
  11. 2026-09-21 20:27 UTCEPSS rescoreEPSS 94% · 99th percentile
  12. 2026-09-20 20:10 UTCEPSS rescoreEPSS 94% · 99th percentile
  13. 2026-09-17 19:22 UTCEPSS rescoreEPSS 94% · 99th percentile
  14. 2026-09-12 14:56 UTCEPSS rescoreEPSS 94% · 99th percentile
  15. 2026-09-12 02:53 UTCOSV refresh
  16. 2026-09-11 14:47 UTCEPSS rescoreEPSS 94% · 99th percentile
  17. 2026-09-06 13:43 UTCEPSS rescoreEPSS 94% · 99th percentile
  18. 2026-09-05 15:24 UTCEPSS rescoreEPSS 94% · 99th percentile
  19. 2026-08-30 19:13 UTCEPSS rescoreEPSS 94% · 99th percentile
  20. 2026-08-28 21:36 UTCEPSS rescoreEPSS 94% · 99th percentile
  21. 2026-08-24 08:27 UTCOSV refresh
  22. 2026-08-21 23:44 UTCEPSS rescoreEPSS 94% · 99th percentile
  23. 2026-08-16 02:10 UTCEPSS rescoreEPSS 94% · 99th percentile
  24. 2026-08-11 13:36 UTCEPSS rescoreEPSS 94% · 99th percentile
  25. 2026-08-08 04:49 UTCOSV refresh
  26. 2026-08-01 04:12 UTCEPSS rescoreEPSS 94% · 99th percentile
  27. 2026-07-30 16:24 UTCEPSS rescoreEPSS 94% · 99th percentile
  28. 2026-07-30 01:27 UTCEPSS rescoreEPSS 94% · 99th percentile
  29. 2026-07-28 15:32 UTCEPSS rescoreEPSS 94% · 99th percentile
  30. 2026-07-23 14:15 UTCEPSS rescoreEPSS 94% · 99th percentile
  31. 2026-07-23 01:32 UTCEG score recompute
  32. 2026-07-22 21:29 UTCEG score recompute▲ 4.70
  33. 2026-07-22 21:29 UTCVendor advisory
  34. 2026-07-21 04:47 UTCOSV refresh
  35. 2026-07-19 02:26 UTCEPSS rescoreEPSS 94% · 99th percentile
  36. 2026-07-12 05:43 UTCEPSS rescoreEPSS 94% · 99th percentile
  37. 2026-07-11 08:24 UTCEPSS rescoreEPSS 94% · 99th percentile
  38. 2026-07-04 00:26 UTCOSV refresh
  39. 2026-07-01 15:03 UTCEPSS rescoreEPSS 94% · 99th percentile
  40. 2026-06-29 14:03 UTCEPSS rescoreEPSS 94% · 99th percentile
  41. 2026-06-25 13:47 UTCEPSS rescoreEPSS 94% · 99th percentile
  42. 2026-06-23 21:30 UTCEPSS rescoreEPSS 94% · 99th percentile
  43. 2026-06-22 14:23 UTCEPSS rescoreEPSS 94% · 99th percentile
  44. 2026-06-21 01:57 UTCEPSS rescoreEPSS 94% · 99th percentile
  45. 2026-06-15 17:45 UTCEPSS rescoreEPSS 94% · 99th percentile
  46. 2026-06-15 12:13 UTCOSV refresh
  47. 2026-06-13 22:58 UTCEPSS rescoreEPSS 83% · 99th percentile
  48. 2026-06-12 23:09 UTCEPSS rescoreEPSS 83% · 99th percentile
  49. 2026-06-11 13:57 UTCEPSS rescoreEPSS 83% · 99th percentile
  50. 2026-06-10 22:16 UTCEPSS rescoreEPSS 83% · 99th percentile
  51. 2026-06-06 13:45 UTCEPSS rescoreEPSS 83% · 99th percentile
  52. 2026-06-05 22:44 UTCEPSS rescoreEPSS 83% · 99th percentile
  53. 2026-06-05 06:08 UTCEPSS rescoreEPSS 83% · 99th percentile
  54. 2026-06-01 13:49 UTCEPSS rescoreEPSS 83% · 99th percentile
  55. 2026-05-31 00:14 UTCEPSS rescoreEPSS 83% · 99th percentile
  56. 2026-05-28 13:42 UTCEPSS rescoreEPSS 83% · 99th percentile
  57. 2026-05-28 02:32 UTCEG score recompute
  58. 2026-05-28 02:32 UTCVendor advisory
  59. 2026-05-27 13:38 UTCEPSS rescoreEPSS 83% · 99th percentile
  60. 2026-05-23 09:31 UTCOSV refresh

Publicly available exploits

(2 references)

Public exploit code is referenced for this CVE (1 Exploit-DB entry), as is 1 Nuclei detection template. A detection template checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.

  • Exploit-DBEDB-50118
    Published Jul 13, 2021

    Apache Tomcat 9.0.0.M1 - Open Redirect

    Open source ↗
  • Nucleihttp/cves/2018/CVE-2018-11784.yaml
    Published Mar 19, 2021

    Apache Tomcat - Open Redirect

    Open source ↗

Related CVEs(same product + same vendor + same CWE)

Same vendor

3 shown

redhat:RHSA-2019:0130 · redhat:RHSA-2018:2867 · redhat:RHSA-2019:1529

Frequently asked(5)

What is CVE-2018-11784?
CVE-2018-11784 is a critical-severity vulnerability; its CVE record was published on October 4, 2018. When the default servlet in Apache Tomcat versions 9.0.0.M1 to 9.0.11, 8.5.0 to 8.5.33 and 7.0.23 to 7.0.90 returned a redirect to a directory (e.g. redirecting to '/foo/' when the user requested '/foo') a specially crafted URL could be used to cause the redirect to be generated to any URI of the…
When was CVE-2018-11784 made public?
CVE-2018-11784 was made public on October 3, 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 October 4, 2018. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2018-11784 actively exploited?
CVE-2018-11784 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2018-11784?
CVE-2018-11784 has a CVSS v3 base score of 4.3 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
How do I remediate CVE-2018-11784?
A fix for CVE-2018-11784 is available: update to the fixed version the vendor names in its advisory.

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