CVE-2026-84448libheif: Heap out-of-bounds read in libheif inline-mask region API (heif_region_item_add_region_inline_mask_data / heif_region_get_mask_image)
- 4.0MediumCVSS base score
- 0.19%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, the public heif_region_item_add_region_inline_mask_data() function in libheif/api/libheif/heif_regions.cc accepts mask_data_len without verifying that it equals the byte count required by width and height. A later heif_region_get_mask_image() call derives the read length from the region geometry, so an undersized stored buffer causes heif_region_get_inline_mask_image() to read beyond the heap allocation and copy adjacent bytes into the returned monochrome mask image. This can disclose heap data or crash an application that constructs region metadata through the writer API, while the file-parsing path is not affected because it validates the canonical mask size. This issue is fixed in version 1.23.2.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/strukturag/libheif/security/advisories/GHSA-p58j-h3vm-3fp5 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 17 days later
· 17 days later
Published
- 6 days later
· 6 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.0 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |
| NVDNVD · Deferred | 3.1 | Medium4.0 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.19% · top 92% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.0.
Affected products
- affected < 1.23.2
References
References3
- https://github.com/strukturag/libheif/security/advisories/GHSA-p58j-h3vm-3fp5 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/strukturag/libheif/commit/646d85fbf5bd18fc3cdc516e915e59072de2d510 (opens in a new tab)x_refsource_MISC
- https://github.com/strukturag/libheif/releases/tag/v1.23.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-83015 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-84448)Record last updated .