- 8.2HighCVSS base score
- 0.43%Exploitation in 30 daysEPSS · top 63% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
bz2.BZ2Decompressor objects could be reused after a decompression error. If an application caught the resulting OSError and retried with the same decompressor, crafted input could cause the decompressor to resume from an invalid internal state and perform out-of-bounds writes to a stack buffer. This could crash the process when processing untrusted data.
Timeline
ID reserved
By PSF
- 12 days later
· 12 days later
Published
- 5 months later
· 5 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| PSFCNA (assigner) | 4.0 | High8.2 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| NVDNVD · Awaiting Analysis | 4.0 | High8.2 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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 |
- EPSS (exploitation in 30 days)
- 0.43% · top 63% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Affected products
Python Software Foundation · CPython
- affected < 3.10.21
- affected 3.11.0 – < 3.11.16
- affected 3.12.0 – < 3.12.14
- affected 3.13.0 – < 3.13.14
- affected 3.14.0 – < 3.14.6
- affected 3.15.0a1 – < 3.15.0b3
References
References12
- https://github.com/python/cpython/pull/150600 (opens in a new tab)patch
- https://mail.python.org/archives/list/[email protected]/thread/DBJZETMGUIFK7DVUWMOXHD3Z6IX2QPSX/ (opens in a new tab)vendor-advisory
- https://github.com/python/cpython/issues/150599 (opens in a new tab)issue-tracking
- https://github.com/python/cpython/commit/157a5df8cb5d82b33f918a7489e72ce95ceb12b6 (opens in a new tab)patch
- https://github.com/python/cpython/commit/5755d0f083949ff3c5bf3a37e673e24e306b036e (opens in a new tab)patch
- https://github.com/python/cpython/commit/619a12b2e545391dc436b3af79dda22337382a6f (opens in a new tab)patch
- https://github.com/python/cpython/commit/d3ca26983dfbccdf609f24ff5877dc3118e4702d (opens in a new tab)patch
- https://github.com/python/cpython/commit/938ec030e90c5e53f1faac6fab1643f14e4f4a79 (opens in a new tab)patch
- https://github.com/python/cpython/commit/991e6cf86496718c4ef00b362d640e00cb5c85b2 (opens in a new tab)patch
- https://github.com/python/cpython/commit/1ba6135eae75ad8413413caeeedb56ae72320636 (opens in a new tab)patch
- http://www.openwall.com/lists/oss-security/2026/06/08/17 (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-35202 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-9669)Record last updated .