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CVE-2026-15310
zipfile: bzip2/LZMA/Zstandard members decompress without a max_length bound, defeating chunked-read memory limits
Low2.1EPSS 0.53%
- Published
- Updated
- Reserved
- Assigned by
- PSF
Description
When decompressing crafted zip files using the bzip/LZMA/Zstandard compressions, Python could use an attacker-controlled size to pre-allocate memory, possibly resulting in memory exhaustion.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| PSFCNA (assigner) | 4.0 | Low2.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| NVDNVD · Awaiting Analysis | 4.0 | Low2.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/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 |
- EPSS (exploitation in 30 days)
- 0.53% · top 55% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.1.
Weakness
Affected products
Python Software Foundation · CPython
- affected < 3.10.22
- affected 3.11.0 – < 3.11.17
- affected 3.12.0 – < 3.12.15
- affected 3.13.0 – < 3.13.16
- affected 3.14.0 – < 3.14.8
- affected 3.15.0a1 – < 3.15.0rc2
References (13)
- https://github.com/python/cpython/pull/156003 (opens in a new tab)patch
- https://github.com/python/cpython/issues/156002 (opens in a new tab)issue-tracking
- https://mail.python.org/archives/list/[email protected]/thread/YUHXURX2WZGKGNA4ANYBQS2VZRYQ5JNK/ (opens in a new tab)vendor-advisory
- https://github.com/python/cpython/commit/f897dbf2f36a5935700b7c2d94d4681d2136b7d4 (opens in a new tab)patch
- https://github.com/python/cpython/commit/1b424c0178a01e155fd0267dc28a8fc1159b33a8 (opens in a new tab)patch
- https://github.com/python/cpython/commit/31980e84b9a708424a0a1dfecde3fc991e313f89 (opens in a new tab)patch
- https://github.com/python/cpython/commit/e2311cfb3dd518f008f312fe0631f4f7490d237a (opens in a new tab)patch
- https://github.com/python/cpython/commit/f507e6946a3194e83e1d7b8ee6e14567175e46de (opens in a new tab)patch
- https://github.com/python/cpython/commit/9d167992b59cf5e23c66b9ed742b13f5925f7d70 (opens in a new tab)patch
- https://github.com/python/cpython/commit/dcdd406ddbfc4cb29b24c3df17cbabe21d316ce1 (opens in a new tab)patch
- https://github.com/python/cpython/commit/09a2e7e6678b4f65449e7ad8f112c48f944591e2 (opens in a new tab)patch
- https://github.com/python/cpython/commit/6257029de42ef89b67f3d20137de87d43e197530 (opens in a new tab)patch
- https://github.com/python/cpython/commit/c2bfbcdd1a11690507a10bc0998f95b8dc6b6fac (opens in a new tab)patch
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)
- 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://trackcve.app/cve/CVE-2026-15310)Record last updated .