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TI-2026-34834 Aliases CVE-2026-47251

libheif has an incomplete fix for CVE-2026-3949: integer overflow bypass in vvdec_push_data2

Priority MEDIUM 63CWE-125Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Active
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
Low · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

libheif is a HEIF and AVIF file format decoder and encoder. The fix for CVE-2026-3949 (commit `b97c8b5`, PR #1712) introduced an integer overflow in the very security check it added. The check itself can be bypassed, allowing a crafted HEIF file with a VVC track to trigger the same out-of-bounds heap read that CVE-2026-3949 was meant to prevent. This is a separate, currently-unpatched vulnerability. Issue #1712 was closed as fixed without testing the edge case where `size` is near `UINT32_MAX`. Version 1.22.0 patches the issue.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00159 5th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed libheif (strukturag): 1.22.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
strukturaglibheifbefore 1.22.01.22.0Patch availableCNA
  • libheif Vendorstrukturag Affected before 1.22.0 Fixed in 1.22.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:struktur:libheif:*:*:*:*:*:*:*:*before 1.22.0Vulnerablestrukturag
  • cpe:2.3:a:struktur:libheif:*:*:*:*:*:*:*:* Versions before 1.22.0 Vulnerable ·strukturag

Remediation

  • Fix · CNA libheif (strukturag) Fixed in 1.22.0

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-47251

References

Exploit 1

Other 1

  • TI-2023-27020 libheif v1.17.5 was discovered to contain a segmentation violation via the function… CVSS 3.1HIGH 8.8
  • TI-2026-34830 libheif Vulnerable to Heap Information Disclosure via Grid Image Gap + Uninitialized Pixel Plane Allocation CVSS 3.1HIGH 7.5
  • TI-2024-16668 libheif <= 1.17.6 contains a memory leak in the function JpegEncoder::Encode. CVSS 3.1HIGH 7.5
  • TI-2024-27575 In Libheif 1.17.6, insufficient checks in ImageOverlay::parse() decoding a heif file… CVSS 3.1HIGH 8.1
  • TI-2026-35472 libheif: heap OOB read in ImageItem_Grid::decode_grid_tile via irot-induced tile-coordinate underflow CVSS 3.1HIGH 7.1
  • TI-2026-35212 libheif has a NULL pointer dereference in heif_image_handle_get_image_tiling for malformed unci image missing ispe CVSS 4.0MEDIUM 6.9
See all 28 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences