CVE-2026-84444

libheif uncompressed tiled image encoding allows out-of-bounds write

HIGH
7.4
CVSS Score
Published: September 18, 2026 at 03:56 PM UTC
Updated: September 22, 2026 at 03:17 PM UTC
1 product affected across 1 vendorLibheif

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Severity
HIGH7.4
Exploit prediction
EPSS 0.5%
SSVC
PoC

Description

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, when WITH_UNCOMPRESSED_CODEC is enabled, heif_context_add_image_tile() accepts an independently constructed tile whose component-plane dimensions do not match the tile geometry established by the prototype image. ImageItem_uncompressed::add_image_tile() passes that tile directly to unc_encoder::encode_tile(), which lacked the check_component_sizes() gate and sizes its output from the configured tile geometry while copying the tile's actual component-plane dimensions. An oversized component plane can therefore make unc_encoder_component_interleave::encode_tile() copy attacker-controlled data beyond the heap output buffer. This issue is fixed in version 1.23.2.

Affected

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

v < 1.23.2
Affected range stops below 1.23.2, 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 automatablePartial impact

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

CVSS

7.4HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-787

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