CVE-2026-40492

SAIL has heap buffer overflow in XWD decoder — bits_per_pixel vs pixmap_depth type confusion in byte-swap

State
Published
Severity
9.8 Critical
Published
Apr 18, 2026
Updated
Apr 20, 2026
Reserved
Apr 13, 2026

Read the record on cve.org

Description

SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch.

Scores

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HGitHub_M

Weaknesses

Affected Products

ProductVersions
sailHappySeaFox
  • < 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02Affected

References

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