VulnerabilityAwaiting Analysis
CVE-2026-15310
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.
LOW 2.1EPSS 0.34%
Does this matter?
Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 2.1 LOWCVSS: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/M
- EPSS
- 0.34% probability · 27th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Source
- cna@python.org
References
- https://github.com/python/cpython/commit/1b424c0178a01e155fd0267dc28a8fc1159b33a8
- https://github.com/python/cpython/commit/31980e84b9a708424a0a1dfecde3fc991e313f89
- https://github.com/python/cpython/commit/e2311cfb3dd518f008f312fe0631f4f7490d237a
- https://github.com/python/cpython/commit/f897dbf2f36a5935700b7c2d94d4681d2136b7d4
- https://github.com/python/cpython/issues/156002
- https://github.com/python/cpython/pull/156003
- https://mail.python.org/archives/list/security-announce@python.org/thread/YUHXURX2WZGKGNA4ANYBQS2VZRYQ5JNK/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.