Critical severity · published Apr 18, 2026
CVE-2026-40493
SAIL has heap buffer overflow in PSD decoder — bpp mismatch in LAB 16-bit mode
9.8
CVSS
0.4%
EPSS
No
On KEV
Description
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, the PSD codec computes bytes-per-pixel (`bpp`) from raw header fields `channels * depth`, but the pixel buffer is allocated based on the resolved pixel format. For LAB mode with `channels=3, depth=16`, `bpp = (3*16+7)/8 = 6`, but the format `BPP40_CIE_LAB` allocates only 5 bytes per pixel. Every pixel write overshoots, causing a deterministic heap buffer overflow on every row. Commit c930284445ea3ff94451ccd7a57c999eca3bc979 contains a patch.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SA
sail · HappySeaFox
< c930284445ea3ff94451ccd7a57c999eca3bc979 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40493
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40493
github.com
https://github.com/HappySeaFox/sail/commit/c930284445ea3ff94451ccd7a57c999eca3bc979
github.com
https://github.com/HappySeaFox/sail/security/advisories/GHSA-rcqx-gc76-r9mv
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