VDB

CVE-2026-4224

CVE-2026-4224 PUBLISHED CVSS 6 MEDIUM

Stack overflow parsing XML with deeply nested DTD content models

Reported by psf · Published 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.

Fixed versions

Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.

PackageEcosystemFixed in
python3.13Amazon Linux3.13.13-1.amzn2023.0.1
python3.14-freethreading-libsAmazon Linux3.14.3-2.amzn2023.0.1
python3.14-freethreading-tkintererrata.rockylinux.org3.14.4-2.el9, 3.14.4-2.el10
python3.14-freethreading-develAmazon Linux3.14.3-2.amzn2023.0.1
python3.12-debuginfoerrata.rockylinux.org3.12.13-2.el9, 3.12.13-2.el10
python3.14-freethreadingerrata.rockylinux.org3.14.4-2.el9
python3.14-debugerrata.rockylinux.org3.14.4-2.el9, 3.14.4-2.el10
python3.12errata.rockylinux.org3.12.13-2.el9, 3.12.13-2.el8, 3.12.13-2.el10, 0:3.12.13-2.el8_10.x86_64, 0:3.12.13-2.el8_10.src, 0:3.12.13-2.el8_10.i686
python3.11-tkinterAmazon Linux3.11.15-1.amzn2023.0.1
python3.14-testerrata.rockylinux.org3.14.4-2.el9, 3.14.4-2.el10
python3.14errata.rockylinux.org3.14.4-2.el9, 3.14.4-2.el10
python3.14-debuginfoerrata.rockylinux.org3.14.4-2.el9, 3.14.4-2.el10

44 more packages have a fixed version. See every fix in Lookup.

Risk scores

CVSS 4.0
6
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Affected products

VendorProductVersions
Python Software FoundationCPython0, 3.11.0, 3.12.0
amazon:2023python3.130
amazon:2023python3.14-freethreading-libs0
amazon:2023python3.14-freethreading-devel0
amazon:2023python3.11-tkinter0
amazon:2023python3.11-debug0
chainguardpython-3.110
amazon:2023python3.12-libs0
amazon:2023python3.13-tkinter0
wolfipython-3.110
amazon:2023python3-libs0
Python Software FoundationCPython3.11.0, 3.13.0, 3.12.0
amazon:2023python3.13-freethreading0
amazon:2023python3.14-debug0
amazon:2python3-debug0
amazon:2python3-tools0
amazon:2023python3-debug0
amazon:2python-tools0
amazon:2023python3.13-test0
chainguardpython-3.130

…and 52 more

Timeline

  • Mar 16, 2026 CVE Published
  • Mar 17, 2026 PoC Published (3 in total, the first dated here)
  • Mar 17, 2026 EPSS Score (30 in total, the first dated here)
  • Mar 17, 2026 Coalition ESS Score (3 in total, the first dated here)
  • Mar 29, 2026 Security Advisory (14 in total, the first dated here)
  • Apr 28, 2026 Distribution Patch (13 in total, the first dated here)

Query this with the API

The same record, from the CLI:

vulnetix vdb vuln CVE-2026-4224
vulnetix vdb fixes CVE-2026-4224

Or with curl, using the org id and key from your account page:

curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
  "https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-4224/fixes/registry"

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References

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