{"id":"CVE-2026-96638","title":"Pillow: BMP RLE decoder memory-amplification DoS via unbounded delta escape / absolute mode","summary":"Pillow is a Python imaging library. From 9.1.0 until 13.0.0, BmpRleDecoder.decode() in src/PIL/BmpImagePlugin.py permits crafted RLE BMP delta escapes and absolute-mode runs to append beyond the remaining dest_length without a per-branch…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-400","CWE-770"],"vendor":"python-pillow","product":"Pillow","affected":["Pillow >= 9.1.0, < 13.0.0"],"published":"2026-10-21","updated":"2026-10-21","sourceUpdated":"2026-10-21T20:47:21.767Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-96638","references":[{"url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-24rc-8hj2-v98c","label":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-24rc-8hj2-v98c"},{"url":"https://github.com/python-pillow/Pillow/pull/10015","label":"https://github.com/python-pillow/Pillow/pull/10015"},{"url":"https://github.com/python-pillow/Pillow/commit/e7794835e323ff2691d9b3a974cade1a44301b9a","label":"https://github.com/python-pillow/Pillow/commit/e7794835e323ff2691d9b3a974cade1a44301b9a"},{"url":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0","label":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0"}],"tags":["cve.org"],"ingestedAt":"2026-10-21T21:13:32.882Z","slug":"CVE-2026-96638","body":"## Overview\n\nPillow is a Python imaging library. From 9.1.0 until 13.0.0, BmpRleDecoder.decode() in src/PIL/BmpImagePlugin.py permits crafted RLE BMP delta escapes and absolute-mode runs to append beyond the remaining dest_length without a per-branch cap. A delta can add roughly 255 image rows in one iteration, so a kilobyte-sized file with a large but permitted width can expand the data bytearray to hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.\n\n## Affected\n\n- `Pillow >= 9.1.0, < 13.0.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}