CVE-2011-3639

NONECVSS 0.0Weaponized
0.0
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • 27 internet-exposed hosts are running an affected version right now
  • High exploitation likelihood — EPSS 53%
CISA-KEV: Not listedEPSS: 53%CVSS: —Exploit: NoneExposed: 27

A fix is available — apply it.

The mod_proxy module in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x before 2.2.18, when the Revision 1179239 patch is in place, does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers by using the HTTP/0.9 protocol with a malformed URI containing an initial @ (at sign) character. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.

Live · internet exposure

27 internet-exposed hosts are running an affected version of CVE-2011-3639 right now.

across 13 countries (United States, Japan, Germany, Denmark, Hungary)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
—
EG Score
0.0(none)
EPSS
98.8%
KEV
Not listed

Published

November 30, 2011

Last Modified

April 29, 2026

References (8)

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhathttpd-0:2.2.3-63.el5_8.12012-02-21redhat
redhathttpd-0:2.2.15-15.el6_2.12012-02-13redhat

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.

Weakness Classification(1)

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

All Vendor Advisories

(2)

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 10× in last 7d / 37× 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. 2026-07-06 16:23 UTCEPSS rescore
  2. 2026-07-06 02:19 UTCEPSS rescore
  3. 2026-07-06 02:19 UTCEPSS rescore
  4. 2026-07-05 17:29 UTCOSV refresh
  5. 2026-07-04 06:27 UTCEPSS rescore
  6. 2026-07-02 14:01 UTCEPSS rescore
  7. 2026-07-01 15:02 UTCEPSS rescore
  8. 2026-07-01 15:02 UTCEPSS rescore
  9. 2026-06-30 23:19 UTCEPSS rescore
  10. 2026-06-30 23:19 UTCEPSS rescore
  11. 2026-06-28 04:53 UTCEPSS rescore
  12. 2026-06-28 04:52 UTCEPSS rescore
  13. 2026-06-27 03:05 UTCEPSS rescore
  14. 2026-06-27 03:05 UTCEPSS rescore
  15. 2026-06-25 13:46 UTCEPSS rescore
  16. 2026-06-23 21:30 UTCEPSS rescore
  17. 2026-06-23 21:30 UTCEPSS rescore
  18. 2026-06-22 14:22 UTCEPSS rescore
  19. 2026-06-22 14:22 UTCEPSS rescore
  20. 2026-06-21 01:56 UTCEPSS rescore
  21. 2026-06-21 01:56 UTCEPSS rescore
  22. 2026-06-18 17:49 UTCEPSS rescore
  23. 2026-06-18 17:49 UTCEPSS rescore
  24. 2026-06-17 17:49 UTCEPSS rescore
  25. 2026-06-17 17:49 UTCEPSS rescore
Show 54 more
  1. 2026-06-17 17:49 UTCEPSS rescore
  2. 2026-06-17 04:43 UTCOSV refresh
  3. 2026-06-16 17:49 UTCEPSS rescore
  4. 2026-06-15 17:44 UTCEPSS rescore
  5. 2026-06-13 22:57 UTCEPSS rescore
  6. 2026-06-13 22:57 UTCEPSS rescore
  7. 2026-06-12 23:08 UTCEPSS rescore
  8. 2026-06-11 13:56 UTCEPSS rescore
  9. 2026-06-10 22:14 UTCEPSS rescore
  10. 2026-06-10 13:17 UTCEPSS rescore
  11. 2026-06-08 14:14 UTCEPSS rescore
  12. 2026-06-08 14:14 UTCEPSS rescore
  13. 2026-06-07 15:22 UTCEPSS rescore
  14. 2026-06-07 15:22 UTCEPSS rescore
  15. 2026-06-06 13:45 UTCEPSS rescore
  16. 2026-06-06 13:44 UTCEPSS rescore
  17. 2026-06-05 22:44 UTCEPSS rescore
  18. 2026-06-05 06:08 UTCEPSS rescore
  19. 2026-06-05 06:07 UTCEPSS rescore
  20. 2026-06-04 13:09 UTCEPSS rescore
  21. 2026-06-04 13:09 UTCEPSS rescore
  22. 2026-06-02 20:10 UTCEPSS rescore
  23. 2026-06-02 20:10 UTCEPSS rescore
  24. 2026-05-31 22:28 UTCEPSS rescore
  25. 2026-05-31 22:28 UTCEPSS rescore
  26. 2026-05-31 00:14 UTCEPSS rescore
  27. 2026-05-31 00:14 UTCEPSS rescore
  28. 2026-05-29 13:41 UTCEPSS rescore
  29. 2026-05-29 13:40 UTCEPSS rescore
  30. 2026-05-29 06:09 UTCEG score recompute
  31. 2026-05-29 06:09 UTCVendor advisory
  32. 2026-05-29 06:09 UTCGHSA enrichment
  33. 2026-05-28 13:42 UTCEPSS rescore
  34. 2026-05-28 13:42 UTCEPSS rescore
  35. 2026-05-28 13:42 UTCEPSS rescore
  36. 2026-05-27 13:38 UTCEPSS rescore
  37. 2026-05-27 13:38 UTCEPSS rescore
  38. 2026-05-26 13:41 UTCEPSS rescore
  39. 2026-05-26 13:41 UTCEPSS rescore
  40. 2026-05-26 07:16 UTCEPSS rescore
  41. 2026-05-26 07:16 UTCEPSS rescore
  42. 2026-05-24 16:43 UTCEPSS rescore
  43. 2026-05-23 22:05 UTCOSV refresh
  44. 2026-05-22 21:15 UTCEPSS rescore
  45. 2026-05-22 21:15 UTCEPSS rescore
  46. 2026-05-22 21:15 UTCEPSS rescore
  47. 2026-05-20 22:37 UTCEPSS rescore
  48. 2026-05-20 22:37 UTCEPSS rescore
  49. 2026-05-20 22:37 UTCEPSS rescore
  50. 2026-05-20 11:21 UTCEPSS rescore
  51. 2026-05-20 11:21 UTCEPSS rescore
  52. 2026-05-20 11:21 UTCEPSS rescore
  53. 2026-05-18 21:29 UTCEPSS rescore
  54. 2026-05-18 21:29 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-36663✓ verified
    First seen Feb 6, 2012

    Apache 2.2.15 mod_proxy - Reverse Proxy Security Bypass

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(4)

What is CVE-2011-3639?
CVE-2011-3639 is a none vulnerability published on November 30, 2011. The mod_proxy module in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x before 2.2.18, when the Revision 1179239 patch is in place, does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers…
When was CVE-2011-3639 disclosed?
CVE-2011-3639 was first published in the National Vulnerability Database on November 30, 2011, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2011-3639 actively exploited?
CVE-2011-3639 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2011-3639?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2011-3639, 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

Explore the affected products and dependency analysis for CVE-2011-3639

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