CVE-2026-7210
What it is
`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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-331
- Record status
- Modified
Affected
- Python < 3.13.14
- Python < 3.14.6
- Python 3.15.0
Attack profile CVSS 4.0 · 6.3
- Attack vector
- Network
- Complexity
- High
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Raw 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Fix and advisories
- https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
- https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
- https://github.com/python/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56
- https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b
- https://github.com/python/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286
- https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
- https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f
- https://github.com/python/cpython/pull/149023
References
- https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
- https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
- https://github.com/python/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56
- https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b
- https://github.com/python/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286
- https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
- https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f
- https://github.com/python/cpython/issues/149018
- https://github.com/python/cpython/pull/149023
- https://mail.python.org/archives/list/[email protected]/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/
- http://www.openwall.com/lists/oss-security/2026/05/11/13
- http://www.openwall.com/lists/oss-security/2026/05/11/8