CVE-2026-4224

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory published 2026-03-16. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: 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
Severity75% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
50%
KEV
Not listed

Published

March 16, 2026

Last Modified

August 13, 2026

Advisory Details (9)

Auto-updated Aug 2, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
generic

oss-security - [CVE-2026-4224] CPython Stack overflow parsing XML with deeply nested DTD content models

http://www.openwall.com/lists/oss-security/2026/03/16/4
generic

Mailman 3 [CVE-2026-4224] Stack overflow parsing XML with deeply nested DTD content models - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/5M7CGUW3XBRY7II4DK43KF7NQQ3TPZ6R/
github_pr

gh-145986: Avoid unbound C recursion in `conv_content_model` in `pyexpat.c` (CVE 2026-4224)

Fix merged in python/cpython PR #145987 on 2026-03-15 — awaiting tagged release

https://github.com/python/cpython/pull/145987
generic

`pyexpat.c`: Unbounded C recursion in `conv_content_model` causes crash (CVE 2026-4224) · Issue #145986 · python/cpython · GitHub

https://github.com/python/cpython/issues/145986
github_commit

commit eb0e8be3a7e1 (python/cpython)

Fix landed in python/cpython commit eb0e8be3a7e1 — awaiting tagged release

https://github.com/python/cpython/commit/eb0e8be3a7e11b87d198a2c3af1ed0eccf532768
github_commit

commit e0a8a6da9059 (python/cpython)

Fix landed in python/cpython commit e0a8a6da9059 — awaiting tagged release

https://github.com/python/cpython/commit/e0a8a6da90597a924b300debe045cdb4628ee1f3
github_commit

commit af856a717732 (python/cpython)

Fix landed in python/cpython commit af856a717732 — awaiting tagged release

https://github.com/python/cpython/commit/af856a7177326ac25d9f66cc6dd28b554d914fee
github_commit

commit 642865ddf4b2 (python/cpython)

Fix landed in python/cpython commit 642865ddf4b2 — awaiting tagged release

https://github.com/python/cpython/commit/642865ddf4b232da1f3b1f7abcfa3254c4bfe785
github_commit

commit 196edfb06a74 (python/cpython)

Fix landed in python/cpython commit 196edfb06a74 — awaiting tagged release

https://github.com/python/cpython/commit/196edfb06a7458377d4d0f4b3cd41724c1f3bd4a

Vendor Advisories for CVE-2026-4224(13)

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

Patch Availability(11)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntupython3.12-venv (3.12.3-1ubuntu0.15) @ noble2026-08-05ubuntu
redhatrhui5/rhua-rhel9:17797982222026-05-27redhat
redhatpython3.12-0:3.12.13-2.el9_82026-05-19redhat
redhatpython3.12-0:3.12.13-2.el10_22026-05-19redhat
redhatpython3.14-0:3.14.4-2.el10_22026-05-19redhat
redhatpython3.14-0:3.14.4-2.el9_82026-05-19redhat
redhatpython3.12-0:3.12.13-2.el8_102026-04-27redhat
redhatpython3-12-main-3.12.13-3.hum12026-04-17redhat
redhatpython3-11-main-3.11.15-4.hum12026-04-17redhat
redhatpython3-14-main-3.14.4-1.hum12026-04-11redhat
redhatpython3-13-main-3.13.13-1.hum12026-04-10redhat

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

(7 across 5 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
python2.72.7.18-10 ... 2.7.18-9 (10 versions)——
python3.93.9.2-1 ... 3.9.2-1+deb11u6 (7 versions)3.9.2-1+deb11u7—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
python3.133.13.11-1 ... 3.13.9-1 (7 versions)3.13.14-1—
python3.143.14.0-1 ... 3.14.3-3 (17 versions)3.14.3-4—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
python3—3.14.5-r0—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
python3.113.11.2-6 ... 3.11.2-6+deb12u7 (8 versions)3.11.2-6+deb12u8—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
python3.133.13.5-2, 3.13.5-2+deb13u13.13.5-2+deb13u2—

Weakness Classification(1)

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 5× in last 7d / 76× 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.

Showing the most recent 100 of 185 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-19 17:04 UTCEPSS rescore
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 11:23 UTCEG score recompute
  10. 2026-08-16 11:23 UTCVendor advisory
  11. 2026-08-16 11:23 UTCGHSA enrichment
  12. 2026-08-16 02:14 UTCEPSS rescore
  13. 2026-08-15 01:30 UTCEPSS rescore
  14. 2026-08-14 20:36 UTCVendor advisory
  15. 2026-08-14 20:36 UTCGHSA enrichment
  16. 2026-08-14 07:30 UTCEG score recompute
  17. 2026-08-14 07:30 UTCVendor advisory
  18. 2026-08-14 07:30 UTCGHSA enrichment
  19. 2026-08-13 22:00 UTCEPSS rescore
  20. 2026-08-13 01:23 UTCVendor advisory
  21. 2026-08-13 01:23 UTCGHSA enrichment
  22. 2026-08-13 00:41 UTCVendor advisory
  23. 2026-08-13 00:41 UTCGHSA enrichment
  24. 2026-08-12 22:17 UTCEG score recompute
  25. 2026-08-12 22:17 UTCVendor advisory
Show 75 more
  1. 2026-08-12 22:17 UTCGHSA enrichment
  2. 2026-08-12 13:51 UTCEPSS rescore
  3. 2026-08-11 21:34 UTCEG score recompute
  4. 2026-08-11 21:34 UTCVendor advisory
  5. 2026-08-11 21:34 UTCGHSA enrichment
  6. 2026-08-11 04:42 UTCEG score recompute
  7. 2026-08-11 04:42 UTCVendor advisory
  8. 2026-08-11 04:42 UTCGHSA enrichment
  9. 2026-08-11 00:00 UTCEPSS rescore
  10. 2026-08-10 09:05 UTCVendor advisory
  11. 2026-08-10 09:05 UTCGHSA enrichment
  12. 2026-08-09 20:05 UTCEG score recompute
  13. 2026-08-09 20:05 UTCVendor advisory
  14. 2026-08-09 20:05 UTCGHSA enrichment
  15. 2026-08-09 13:46 UTCEPSS rescore
  16. 2026-08-09 07:05 UTCEG score recompute
  17. 2026-08-09 07:05 UTCVendor advisory
  18. 2026-08-09 07:05 UTCGHSA enrichment
  19. 2026-08-08 16:37 UTCEPSS rescore
  20. 2026-08-08 06:43 UTCVendor advisory
  21. 2026-08-08 06:43 UTCGHSA enrichment
  22. 2026-08-07 17:43 UTCEG score recompute
  23. 2026-08-07 17:43 UTCVendor advisory
  24. 2026-08-07 17:43 UTCGHSA enrichment
  25. 2026-08-06 19:35 UTCEG score recompute
  26. 2026-08-06 19:35 UTCVendor advisory
  27. 2026-08-06 19:35 UTCGHSA enrichment
  28. 2026-08-06 13:47 UTCEPSS rescore
  29. 2026-08-06 01:44 UTCEG score recompute
  30. 2026-08-06 01:44 UTCVendor advisory
  31. 2026-08-06 01:44 UTCGHSA enrichment
  32. 2026-08-05 19:17 UTCEPSS rescore
  33. 2026-08-05 01:19 UTCVendor advisory
  34. 2026-08-05 01:19 UTCGHSA enrichment
  35. 2026-08-05 00:51 UTCEG score recompute
  36. 2026-08-05 00:51 UTCVendor advisory
  37. 2026-08-05 00:51 UTCGHSA enrichment
  38. 2026-08-04 15:10 UTCEPSS rescore
  39. 2026-08-04 10:39 UTCEPSS rescore
  40. 2026-08-04 00:55 UTCEG score recompute
  41. 2026-08-04 00:55 UTCVendor advisory
  42. 2026-08-04 00:55 UTCGHSA enrichment
  43. 2026-08-03 10:36 UTCEPSS rescore
  44. 2026-08-02 16:53 UTCEG score recompute
  45. 2026-08-02 16:53 UTCVendor advisory
  46. 2026-08-02 16:53 UTCGHSA enrichment
  47. 2026-08-02 02:27 UTCEPSS rescore
  48. 2026-08-01 04:16 UTCEPSS rescore
  49. 2026-07-30 16:28 UTCEPSS rescore
  50. 2026-07-30 01:30 UTCEPSS rescore
  51. 2026-07-28 15:37 UTCEPSS rescore
  52. 2026-07-26 14:54 UTCEPSS rescore
  53. 2026-07-25 14:18 UTCEPSS rescore
  54. 2026-07-24 14:18 UTCEPSS rescore
  55. 2026-07-23 14:18 UTCEPSS rescore
  56. 2026-07-23 03:11 UTCEG score recompute
  57. 2026-07-22 14:08 UTCEPSS rescore
  58. 2026-07-21 15:25 UTCEPSS rescore
  59. 2026-07-20 17:08 UTCEPSS rescore
  60. 2026-07-19 14:31 UTCEPSS rescore
  61. 2026-07-19 14:31 UTCEPSS rescore
  62. 2026-07-19 02:29 UTCEPSS rescore
  63. 2026-07-18 10:04 UTCEPSS rescore
  64. 2026-07-17 07:46 UTCOSV refresh
  65. 2026-07-16 17:03 UTCEPSS rescore
  66. 2026-07-15 16:57 UTCEPSS rescore
  67. 2026-07-15 16:57 UTCEPSS rescore
  68. 2026-07-15 02:00 UTCEPSS rescore
  69. 2026-07-13 22:30 UTCEPSS rescore
  70. 2026-07-13 06:13 UTCEPSS rescore
  71. 2026-07-12 05:46 UTCEPSS rescore
  72. 2026-07-11 08:27 UTCEPSS rescore
  73. 2026-07-09 19:10 UTCEPSS rescore
  74. 2026-07-08 15:16 UTCEPSS rescore
  75. 2026-07-07 13:46 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-4224?
CVE-2026-4224 is a high vulnerability published on March 16, 2026. When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs.
When was CVE-2026-4224 disclosed?
CVE-2026-4224 was first published in the National Vulnerability Database on March 16, 2026, with the most recent update on August 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4224 actively exploited?
CVE-2026-4224 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 50.0% of all scored CVEs.
What is the CVSS score of CVE-2026-4224?
CVE-2026-4224 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-4224?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4224, 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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