CVE-2026-32741
What it is
libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.21.2 and below contain a heap buffer overflow in MaskImageCodec::decode_mask_image(). When decoding a HEIF file containing a mask image (mski), the function copies the full iloc extent data into a pixel buffer using memcpy(dst, data.data(), data.size()). The copy length data.size() is determined by the iloc extent in the file (attacker-controlled), while the destination buffer is sized based on the declared image dimensions. Because no upper-bound check exists on the data length, a crafted file whose iloc extent exceeds the pixel buffer allocation overflows the heap. The vulnerable single-memcpy branch is reached when the mskC property specifies bits_per_pixel = 8 and the ispe property declares an even width ≥ 64 (so that stride == width), with no changes to default security limits or external codec plugins required. This issue has been fixed in version 1.22.0.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. High risk of service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-122
- Record status
- Deferred
Attack profile CVSS 3.1 · 7.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-32741.md and follow it. Check whether this project is affected by CVE-2026-32741. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/strukturag/libheif/releases/tag/v1.22.0
- https://github.com/strukturag/libheif/security/advisories/GHSA-j3w5-7whq-p37q
- https://github.com/strukturag/libheif/security/advisories/GHSA-j3w5-7whq-p37q
References
- https://github.com/strukturag/libheif/releases/tag/v1.22.0
- https://github.com/strukturag/libheif/security/advisories/GHSA-j3w5-7whq-p37q
- https://access.redhat.com/security/cve/CVE-2026-32741
- https://bugzilla.redhat.com/show_bug.cgi?id=2480002
- https://github.com/strukturag/libheif/security/advisories/GHSA-j3w5-7whq-p37q
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32741.json