CVE-2016-8740

HIGHNVD 7.58.8▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.8 because EPSS predicts 79% probability of exploitation within the next 30 days (top 0.4% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, ghsa, nvd
Elevated
8.8EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • 42 internet-exposed hosts are running an affected version right now
  • High exploitation likelihood — EPSS 79%
CISA-KEV: Not listedEPSS PROB: 79%CVSS: 7.5Exploit: Elevated riskExposed: 42

A fix is available — apply it.

The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict request-header length, which allows remote attackers to cause a denial of service (memory consumption) via crafted CONTINUATION frames in an HTTP/2 request.

Live · internet exposure

42 internet-exposed hosts are running an affected version of CVE-2016-8740 right now.

across 16 countries (United States, Germany, France, Netherlands, Indonesia)top: http_server
See the live KEV-Exposure radar →Found passively from public internet-scan data — aggregate, host-redacted.

EchelonGraph is the only CVE feed that fuses live vulnerability intelligence with its own live internet-exposure radar — so you see not just that a CVE is exploited, but how much of the internet is exposed to it right now.

CVSS v3
7.5
EG Score
8.8(high)
EG Risk
76(Track)
EG Risk 76/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation79% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
79%
EPSS %ILE
100%
KEV
Not listed

Published

December 5, 2016

Last Modified

June 17, 2026

References (56)

Vendor Advisories for CVE-2016-8740(3)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatjbcs-httpd24-openssl-1:1.0.2h-13.jbcs.el62017-06-07redhat
redhatjbcs-httpd24-openssl-1:1.0.2h-13.jbcs.el72017-06-07redhat
redhatpatch2017-06-07redhat
redhathttpd24-httpd-0:2.4.25-9.el72017-04-26redhat

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 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
apache2—2.4.25-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
apache2—2.4.25-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
apache2—2.4.25-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
apache2—2.4.25-1—

Weakness Classification(2)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 2× in last 7d / 14× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-08-19 16:59 UTCEPSS rescore
  2. 2026-08-16 02:10 UTCEPSS rescore
  3. 2026-08-14 08:16 UTCOSV refresh
  4. 2026-08-11 13:36 UTCEPSS rescore
  5. 2026-08-04 15:05 UTCEPSS rescore
  6. 2026-07-30 16:24 UTCEPSS rescore
  7. 2026-07-30 01:26 UTCEPSS rescore
  8. 2026-07-30 01:26 UTCEPSS rescore
  9. 2026-07-29 16:37 UTCOSV refresh
  10. 2026-07-26 14:50 UTCEPSS rescore
  11. 2026-07-25 14:13 UTCEPSS rescore
  12. 2026-07-24 14:13 UTCEPSS rescore
  13. 2026-07-23 01:24 UTCEG score recompute▲ 1.30
  14. 2026-07-22 22:04 UTCEG score recompute
  15. 2026-07-22 14:04 UTCEPSS rescore
  16. 2026-07-21 15:21 UTCEPSS rescore
  17. 2026-07-21 15:21 UTCEPSS rescore
  18. 2026-07-19 14:28 UTCEPSS rescore
  19. 2026-07-19 14:28 UTCEPSS rescore
  20. 2026-07-16 16:59 UTCEPSS rescore
  21. 2026-07-16 16:59 UTCEPSS rescore
  22. 2026-07-15 16:54 UTCEPSS rescore
  23. 2026-07-15 16:54 UTCEPSS rescore
  24. 2026-07-13 22:26 UTCEPSS rescore
  25. 2026-07-12 06:07 UTCOSV refresh
Show 51 more
  1. 2026-07-11 08:24 UTCEPSS rescore
  2. 2026-07-08 15:10 UTCEPSS rescore
  3. 2026-07-04 06:28 UTCEPSS rescore
  4. 2026-07-01 15:02 UTCEPSS rescore
  5. 2026-06-27 03:05 UTCEPSS rescore
  6. 2026-06-25 13:47 UTCEPSS rescore
  7. 2026-06-23 21:30 UTCEPSS rescore
  8. 2026-06-23 11:58 UTCOSV refresh
  9. 2026-06-21 14:54 UTCEPSS rescore
  10. 2026-06-21 14:54 UTCEPSS rescore
  11. 2026-06-21 01:57 UTCEPSS rescore
  12. 2026-06-21 01:57 UTCEPSS rescore
  13. 2026-06-18 17:50 UTCEPSS rescore
  14. 2026-06-18 17:50 UTCEPSS rescore
  15. 2026-06-17 17:50 UTCEPSS rescore
  16. 2026-06-17 17:50 UTCEPSS rescore
  17. 2026-06-15 17:45 UTCEPSS rescore
  18. 2026-06-14 23:14 UTCEPSS rescore
  19. 2026-06-14 23:14 UTCEPSS rescore
  20. 2026-06-12 23:09 UTCEPSS rescore
  21. 2026-06-11 13:57 UTCEPSS rescore
  22. 2026-06-08 14:14 UTCEPSS rescore
  23. 2026-06-07 15:22 UTCEPSS rescore
  24. 2026-06-07 15:22 UTCEPSS rescore
  25. 2026-06-06 13:45 UTCEPSS rescore
  26. 2026-06-06 13:45 UTCEPSS rescore
  27. 2026-06-06 13:44 UTCOSV refresh
  28. 2026-06-05 06:08 UTCEPSS rescore
  29. 2026-06-05 06:08 UTCEPSS rescore
  30. 2026-06-01 13:49 UTCEPSS rescore
  31. 2026-06-01 13:49 UTCEPSS rescore
  32. 2026-05-31 22:28 UTCEPSS rescore
  33. 2026-05-31 22:28 UTCEPSS rescore
  34. 2026-05-31 00:14 UTCEPSS rescore
  35. 2026-05-29 13:41 UTCEPSS rescore
  36. 2026-05-28 13:42 UTCEPSS rescore
  37. 2026-05-28 13:42 UTCEPSS rescore
  38. 2026-05-27 13:38 UTCEPSS rescore
  39. 2026-05-27 13:38 UTCEPSS rescore
  40. 2026-05-26 13:42 UTCEPSS rescore
  41. 2026-05-26 13:42 UTCEPSS rescore
  42. 2026-05-22 21:15 UTCEPSS rescore
  43. 2026-05-22 17:46 UTCEG score recompute
  44. 2026-05-22 17:46 UTCVendor advisory
  45. 2026-05-22 17:46 UTCGHSA enrichment
  46. 2026-05-20 22:37 UTCEPSS rescore
  47. 2026-05-20 22:37 UTCEPSS rescore
  48. 2026-05-20 22:37 UTCEPSS rescore
  49. 2026-05-18 21:30 UTCEPSS rescore
  50. 2026-05-18 21:30 UTCEPSS rescore
  51. 2026-05-18 21:30 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-40909
    First seen Dec 12, 2016

    Apache 2.4.23 mod_http2 - Denial of Service

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2016-8740?
CVE-2016-8740 is a high vulnerability published on December 5, 2016. The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict request-header length, which allows remote attackers to cause a denial of service (memory consumption) via crafted CONTINUATION frames in an HTTP/2 request.
When was CVE-2016-8740 disclosed?
CVE-2016-8740 was first published in the National Vulnerability Database on December 5, 2016, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-8740 actively exploited?
CVE-2016-8740 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 79% probability of exploitation in the next 30 days, which ranks it in the top 0.4% of all scored CVEs.
What is the CVSS score of CVE-2016-8740?
CVE-2016-8740 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.8.
How do I remediate CVE-2016-8740?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-8740, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2016-8740

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