CVE-2013-4238

NONECVSS 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 5%CVSS: —Exploit: NoneExposed: 0

A fix is available — apply it.

The ssl.match_hostname function in the SSL module in Python 2.6 through 3.4 does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

CVSS v3
—
EG Score
0.0(none)
EPSS
91.7%
KEV
Not listed

Published

August 18, 2013

Last Modified

April 29, 2026

References (30)

Vendor Advisories for CVE-2013-4238(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 / EcosystemFixed in / PatchReleasedSource
ubuntupython3.3-minimal (3.3.1-1ubuntu5.2) @ raring2026-05-28ubuntu
ubuntupython3.2-minimal (3.2.3-6ubuntu3.4) @ quantal2026-05-28ubuntu
ubuntupython2.7-minimal (2.7.3-5ubuntu4.3) @ quantal2026-05-28ubuntu
ubuntupython2.6-minimal (2.6.5-1ubuntu6.2) @ lucid2026-05-28ubuntu
redhatrhev-hypervisor6-0:6.5-20131115.0.3.2.el6_52013-11-21redhat
redhatpython-0:2.6.6-51.el62013-11-20redhat

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.

Additional Vendor Advisories

(5)

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

Frequently asked(4)

What is CVE-2013-4238?
CVE-2013-4238 is a none vulnerability published on August 18, 2013. The ssl.match_hostname function in the SSL module in Python 2.6 through 3.4 does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate…
When was CVE-2013-4238 disclosed?
CVE-2013-4238 was first published in the National Vulnerability Database on August 18, 2013, 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-2013-4238 actively exploited?
CVE-2013-4238 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 91.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2013-4238?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2013-4238, 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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