CVE-2026-4224

HIGHNVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

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, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week

Also known asEUVD-2026-12486 (ENISA EUVD) · GHSA-h46w-ffvp-4pw5 (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 7.5Exploit: None knownExposed services: Not assessed

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
7.5HIGHmedium confidence
EG Risk
34
EG Risk 34/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.7% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.7%
EPSS %ILE
53rd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

March 16, 2026

Last Modified

August 13, 2026

Advisory Details (9)

Auto-updated Aug 2, 2026
Patch available. Sources: github_commit, github_pr.
Web page

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
Web page

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/security-announce@python.org/thread/5M7CGUW3XBRY7II4DK43KF7NQQ3TPZ6R/
GitHub pull request

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
Web page

`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

Patch Availability(13)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntupython3.14-venv (3.14.4-1ubuntu0.1) @ resolute2026-11-01ubuntu
ubuntupython3.5-venv (3.5.2-2ubuntu0~16.04.13+esm25) @ xenial2026-11-01ubuntu
redhatrhui5/rhua-tp-rhel9:17872412602026-08-24redhat
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

(10 across 8 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
python2.72.7.18-10 ... 2.7.18-9 (10 versions)
  • every version on: no fix on record
—
python3.93.9.2-1 ... 3.9.2-1+deb11u6 (7 versions)
  • every version up to 3.9.2-1+deb11u7: fixed in 3.9.2-1+deb11u7
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
python3.133.13.11-1 ... 3.13.9-1 (7 versions)
  • every version up to 3.13.14-1: fixed in 3.13.14-1
—
python3.143.14.0-1 ... 3.14.3-3 (17 versions)
  • every version up to 3.14.3-4: fixed in 3.14.3-4
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.12.14-r0: fixed in 3.12.14-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.12.14-r0: fixed in 3.12.14-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.12.14-r0: fixed in 3.12.14-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.14.5-r0: fixed in 3.14.5-r0
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
python3.113.11.2-6 ... 3.11.2-6+deb12u7 (8 versions)
  • every version up to 3.11.2-6+deb12u8: fixed in 3.11.2-6+deb12u8
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
python3.133.13.5-2, 3.13.5-2+deb13u1
  • every version up to 3.13.5-2+deb13u2: fixed in 3.13.5-2+deb13u2
—

Weakness Classification(1)

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

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 10× in last 7d / 45× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 259 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 159 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  2. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  3. 2026-11-01 06:26 UTCEG score recompute
  4. 2026-11-01 06:26 UTCVendor advisory
  5. 2026-11-01 06:26 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  6. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  7. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  8. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  9. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  10. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.7% · 53rd percentile
  11. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  12. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  13. 2026-10-25 14:29 UTCEG score recompute
  14. 2026-10-24 22:28 UTCEG score recompute
  15. 2026-10-24 22:28 UTCVendor advisory
  16. 2026-10-24 22:28 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  17. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  18. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  19. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  23. 2026-10-18 03:41 UTCEG score recompute
  24. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  25. 2026-10-17 14:28 UTCEG score recompute
Show 75 more
  1. 2026-10-17 14:28 UTCVendor advisory
  2. 2026-10-17 14:28 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  3. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  5. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  6. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-10-12 16:07 UTCEG score recompute
  9. 2026-10-11 19:49 UTCEG score recompute
  10. 2026-10-11 17:03 UTCEG score recompute
  11. 2026-10-11 14:29 UTCEG score recompute
  12. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-10-11 10:44 UTCOSV refresh
  14. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  15. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  16. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  18. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  19. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  21. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  22. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  23. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  24. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  25. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  26. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  27. 2026-09-26 00:27 UTCEPSS rescoreEPSS 1.2% · 67th percentile
  28. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  29. 2026-09-21 22:45 UTCOSV refresh
  30. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  31. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  32. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  33. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  34. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  35. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  36. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  37. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  38. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  39. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  40. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  41. 2026-09-02 18:38 UTCOSV refresh
  42. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  43. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  44. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  45. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  46. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  47. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  48. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  49. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  50. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  51. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  52. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  53. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  54. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  55. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  56. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  57. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  58. 2026-08-16 11:23 UTCEG score recompute
  59. 2026-08-16 11:23 UTCVendor advisory
  60. 2026-08-16 11:23 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  61. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  62. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  63. 2026-08-14 20:36 UTCVendor advisory
  64. 2026-08-14 20:36 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  65. 2026-08-14 07:30 UTCEG score recompute
  66. 2026-08-14 07:30 UTCVendor advisory
  67. 2026-08-14 07:30 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  68. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  69. 2026-08-13 01:23 UTCVendor advisory
  70. 2026-08-13 01:23 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  71. 2026-08-13 00:41 UTCVendor advisory
  72. 2026-08-13 00:41 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5
  73. 2026-08-12 22:17 UTCEG score recompute
  74. 2026-08-12 22:17 UTCVendor advisory
  75. 2026-08-12 22:17 UTCGHSA enrichmentGHSA-h46w-ffvp-4pw5 · GitHub CVSS 7.5

Frequently asked(5)

What is CVE-2026-4224?
CVE-2026-4224 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-4224 published?
The CVE record for CVE-2026-4224 was published on March 16, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 13, 2026; the record at its source may have been updated since.
Is CVE-2026-4224 actively exploited?
CVE-2026-4224 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (53rd percentile of EPSS-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?
A fix for CVE-2026-4224 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-4224 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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