CVE-2026-84383: strukturag libheif · Out-of-bounds Write
Affects strukturag libheifSource CVE Database V5
Public exploit available · CVSS 9.8 Critical : upgrade to 1.23.2 as a priority.
Data as of 5 Nov 2026, 00:01 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-09-18.
- Patch
- Available – fixed in 1.23.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by GitHub, Inc.
, 17 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 12 minutes after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade strukturag libheif to 1.23.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| strukturaglibheif | Affected
| Fixed in
|
AI-suggested
Upgrade libheif to version 1.23.2 or later, where this vulnerability is fixed. No other mitigations are indicated by the vendor advisory.
Description
A heap out-of-bounds write vulnerability exists in libheif versions 1.22.0 through 1.23.1. It occurs when processing crafted HEIF, HEIC, or AVIF files with nested iden and auxl references, leading to duplicate Alpha planes with mismatched bit depths. This causes memory corruption during image decoding. The issue is fixed in version 1.23.2.