CVE-2008-3656

NONECVSS 0.0Weaponized
0.0
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 70%
CISA-KEV: Not listedEPSS: 70%CVSS: —Exploit: NoneExposed: 0

A fix is available — apply it.

Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted HTTP request that is processed by a backtracking regular expression.

CVSS v3
—
EG Score
0.0(none)
EPSS
99.3%
KEV
Not listed

Published

August 13, 2008

Last Modified

April 23, 2026

References (60)

Vendor Advisories for CVE-2008-3656(3)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibruby1.8 (1.8.6.111-2ubuntu1.2) @ hardy2026-05-30ubuntu
redhatruby4-0-main-4.0.0-33.3.hum12026-04-17redhat
redhatruby3-4-main-3.4.8-31.1.hum12026-04-09redhat
redhatruby3-3-main-3.3.10-23.1.hum12026-04-09redhat
redhatruby-0:1.8.5-5.el5_2.52008-10-21redhat

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.

Additional Vendor Advisories

(2)

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 / 24× 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. 2026-07-09 19:04 UTCEPSS rescore
  2. 2026-07-08 15:09 UTCEPSS rescore
  3. 2026-07-04 06:27 UTCEPSS rescore
  4. 2026-07-02 14:00 UTCEPSS rescore
  5. 2026-07-01 15:02 UTCEPSS rescore
  6. 2026-07-01 15:02 UTCEPSS rescore
  7. 2026-06-29 14:02 UTCEPSS rescore
  8. 2026-06-29 14:02 UTCEPSS rescore
  9. 2026-06-28 04:52 UTCEPSS rescore
  10. 2026-06-25 13:46 UTCEPSS rescore
  11. 2026-06-25 13:46 UTCEPSS rescore
  12. 2026-06-24 14:02 UTCEPSS rescore
  13. 2026-06-24 14:02 UTCEPSS rescore
  14. 2026-06-23 21:29 UTCEPSS rescore
  15. 2026-06-23 21:29 UTCEPSS rescore
  16. 2026-06-21 14:53 UTCEPSS rescore
  17. 2026-06-21 14:53 UTCEPSS rescore
  18. 2026-06-18 17:49 UTCEPSS rescore
  19. 2026-06-18 17:49 UTCEPSS rescore
  20. 2026-06-17 17:49 UTCEPSS rescore
  21. 2026-06-17 17:49 UTCEPSS rescore
  22. 2026-06-16 17:49 UTCEPSS rescore
  23. 2026-06-16 17:49 UTCEPSS rescore
  24. 2026-06-15 17:44 UTCEPSS rescore
  25. 2026-06-13 22:57 UTCEPSS rescore
Show 35 more
  1. 2026-06-12 23:08 UTCEPSS rescore
  2. 2026-06-12 23:08 UTCEPSS rescore
  3. 2026-06-11 13:56 UTCEPSS rescore
  4. 2026-06-10 22:14 UTCEPSS rescore
  5. 2026-06-10 13:17 UTCEPSS rescore
  6. 2026-06-08 14:13 UTCEPSS rescore
  7. 2026-06-07 15:22 UTCEPSS rescore
  8. 2026-06-06 13:44 UTCEPSS rescore
  9. 2026-06-06 13:44 UTCEPSS rescore
  10. 2026-06-05 22:44 UTCEPSS rescore
  11. 2026-06-05 22:44 UTCEPSS rescore
  12. 2026-06-05 06:07 UTCEPSS rescore
  13. 2026-06-04 13:09 UTCEPSS rescore
  14. 2026-06-04 13:09 UTCEPSS rescore
  15. 2026-06-02 20:10 UTCEPSS rescore
  16. 2026-06-02 20:10 UTCEPSS rescore
  17. 2026-06-01 13:49 UTCEPSS rescore
  18. 2026-06-01 13:49 UTCEPSS rescore
  19. 2026-06-01 13:49 UTCEPSS rescore
  20. 2026-05-31 00:13 UTCEPSS rescore
  21. 2026-05-31 00:13 UTCEPSS rescore
  22. 2026-05-30 20:40 UTCEG score recompute
  23. 2026-05-30 20:40 UTCVendor advisory
  24. 2026-05-30 20:40 UTCGHSA enrichment
  25. 2026-05-29 13:40 UTCEPSS rescore
  26. 2026-05-27 13:38 UTCEPSS rescore
  27. 2026-05-27 13:37 UTCEPSS rescore
  28. 2026-05-26 07:16 UTCEPSS rescore
  29. 2026-05-26 07:16 UTCEPSS rescore
  30. 2026-05-24 16:43 UTCEPSS rescore
  31. 2026-05-22 21:15 UTCEPSS rescore
  32. 2026-05-22 21:15 UTCEPSS rescore
  33. 2026-05-20 22:37 UTCEPSS rescore
  34. 2026-05-20 22:36 UTCEPSS rescore
  35. 2026-05-18 21:29 UTCEPSS rescore

Publicly available exploits

(2 references)

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

  • Exploit-DBEDB-32222✓ verified
    First seen Aug 11, 2008

    Ruby 1.9 - 'WEBrick::HTTP::DefaultFileHandler' Crafted HTTP Request Denial of Service

    Open source ↗
  • Metasploitauxiliary/dos/http/webrick_regex✓ verified
    First seen Aug 8, 2008

    Ruby WEBrick::HTTP::DefaultFileHandler DoS

    Open source ↗

Frequently asked(4)

What is CVE-2008-3656?
CVE-2008-3656 is a none vulnerability published on August 13, 2008. Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.splitheadervalue function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of…
When was CVE-2008-3656 disclosed?
CVE-2008-3656 was first published in the National Vulnerability Database on August 13, 2008, with the most recent update on April 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2008-3656 actively exploited?
CVE-2008-3656 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2008-3656?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2008-3656, 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

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