CVE-2026-54692

SAIL: XBM X10 decoder writes 2 bytes per literal into a 1-byte-per-literal buffer (heap out-of-bounds write)

HIGH
7.8
CVSS Score
Published: September 17, 2026 at 07:47 PM UTC
Updated: September 24, 2026 at 09:37 PM UTC
1 product affected across 1 vendorSAIL

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to 1.0.0, sail_codec_load_frame_v8_xbm() in src/sail-codecs/xbm/xbm.c allocates the decoded pixel buffer using the X11 one-byte-per-literal layout, but an X10 static short file causes the flat decode loop to write two file-controlled bytes per literal. When ceil(width/8) produces an odd row stride, the X10 literal count includes a padding byte for every row, but the destination has no space for those bytes, so loading the XBM through sail_load_from_file, sail_load_from_memory, or sail_start_loading_* produces a forward heap overwrite that scales with image height. The X11 static char path is not affected. The overwrite can corrupt process state, cause reliable crashes, and potentially enable code execution in a susceptible consuming application. This issue is fixed in version 1.0.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.0.0
Affected range stops below 1.0.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHGitHub_M
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-131CWE-787

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