Log in Start free

Vulnerability · Published May 11, 2026 · Assigned by PSF

CVE-2026-7210The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection

Medium 6.3

In plain English

A medium-severity security flaw in CPython from Python Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.3Medium
Exploit odds (30 days)0.7%top 47.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

`xml.parsers.expat` and `xml.etree.ElementTree` use insufficient entropy for Expat hash-flooding protection, which allows a crafted XML document to trigger hash flooding.\r\n\r\nFully mitigating this vulnerability requires both updating libexpat to 2.8.0 or later and applying this patch.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.21python33.12.14-r0ALPINE-CVE-2026-7210
Alpine:v3.22python33.12.14-r0ALPINE-CVE-2026-7210
Alpine:v3.23python33.12.14-r0ALPINE-CVE-2026-7210
Alpine:v3.24python33.14.7-r0ALPINE-CVE-2026-7210
Debian:12python3.11no fix listedDEBIAN-CVE-2026-7210
Debian:13python3.13no fix listedDEBIAN-CVE-2026-7210
Debian:14python3.143.14.6-1DEBIAN-CVE-2026-7210
Ubuntu:22.04:LTSpython3.10no fix listedUBUNTU-CVE-2026-7210
Ubuntu:24.04:LTSpython3.12no fix listedUBUNTU-CVE-2026-7210
Ubuntu:25.10python3.13no fix listedUBUNTU-CVE-2026-7210
Ubuntu:25.10python3.14no fix listedUBUNTU-CVE-2026-7210
Ubuntu:26.04:LTSpython3.14no fix listedUBUNTU-CVE-2026-7210

Affected products (as reported)

VendorProductVersions
Python Software Foundation CPython 0 – before 3.10.223.11.0 – before 3.11.163.12.0 – before 3.12.143.13.0 – before 3.13.143.14.0 – before 3.14.63.15.0a1 – before 3.15.0b2

Weakness: CWE-331 · Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References