{"id":"CVE-2026-96639","summary":"Pillow multi-frame loaders can reuse stale native image storage after mode transitions","details":"Pillow is a Python imaging library. From 11.0.0 until 13.0.0, multi-frame loaders can retain an ImagingCore allocation created for a narrow frame mode while a later frame of the same dimensions changes the logical mode and decoder tiles to wider RGB or CMYK data. ImageFile.load_prepare() reuses the stale native storage because _im is non-null without verifying that its mode and size still match. Crafted PSD, MPO, DCX, or MIC frame transitions can then write wider pixels into the narrow allocation, causing native out-of-bounds writes and crashes. The MPO path can also cause a native over-read and, in demonstrated runtime-specific profiles, command execution. This issue is fixed in version 13.0.0.","aliases":["GHSA-v9pv-5gc8-w2m6"],"modified":"2026-10-22T11:19:42.630235461Z","published":"2026-10-21T21:06:42.111Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-125","CWE-787"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/96xxx/CVE-2026-96639.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/96xxx/CVE-2026-96639.json"},{"type":"FIX","url":"https://github.com/python-pillow/Pillow/commit/78d97d994579aef81aafe123773d525f40f2522a"},{"type":"FIX","url":"https://github.com/python-pillow/Pillow/pull/10105"},{"type":"WEB","url":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0"},{"type":"ADVISORY","url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-v9pv-5gc8-w2m6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-96639"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/python-pillow/pillow","events":[{"introduced":"204aae6682fc936f5350b3fe70335776f81480a7"},{"fixed":"293218ad059d994baf1777d882911bed6a49704a"},{"fixed":"78d97d994579aef81aafe123773d525f40f2522a"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StringRangeExpression","range":[{"introduced":"11.0.0"},{"fixed":"13.0.0"}]},{"source":"REFERENCES_COMMIT","range":[{"fixed":"78d97d994579aef81aafe123773d525f40f2522a"}]},{"source":"REFERENCES_TAG","original_tag":"13.0.0","range":[{"fixed":"293218ad059d994baf1777d882911bed6a49704a"}]}]}}],"versions":["12.3.0","12.2.0","12.1.0","12.0.0","11.3.0","11.2.1","11.1.0","11.0.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-96639.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}