CVE-2026-7210
`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…
Does this matter?
Lower severity and a low EPSS score (0.67%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.3 MEDIUMCVSS: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/M
- EPSS
- 0.67% probability · 52th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-331
- Affected
- python/python
- Source
- cna@python.org
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4Patch
- https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566Patch
- 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/eeea765cb9d8f1fc3d8918b272ac3c477983f27aPatch
- https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145fPatch
- https://github.com/python/cpython/issues/149018Issue Tracking
- https://github.com/python/cpython/pull/149023Issue Tracking, Patch
- https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2026/05/11/13Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2026/05/11/8Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.