CVE-2026-49271

libheif: Wrapped icef compressed-unit range check causes out-of-bounds read in uncompressed HEIF decoder

MEDIUM
6.5
CVSS Score
Published: June 19, 2026 at 05:16 PM UTC
Updated: October 25, 2026 at 11:10 PM UTC
2 products affected across 2 vendorsLibheifLibheif

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

libheif is a HEIF and AVIF file format decoder and encoder. Prior to version 1.22.1, the uncompressed HEIF decoder validates explicit icef compressed-unit offsets using unit_offset + unit_size. Because the addition can wrap, a crafted HEIF file can pass the range check and then construct a vector from iterators outside the compressed item buffer, producing an out-of-bounds heap read and crash. Version 1.22.1 patches the issue.

Affected

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

All versionsv < 1.22.1
Affected range stops below 1.22.1, so it looks safe — our inference, not a vendor statement
v < 1.22.1
Affected range stops below 1.22.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/strukturag/libheif/security/advisories/GHSA-r7qj-cg5r-r6vf

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

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

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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