CVE-2026-47251

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this weekElevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

July 21, 2026

Last Modified

July 27, 2026

Advisory Details (2)

Auto-updated Jul 22, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Incomplete fix for CVE-2026-3949: integer overflow bypass in vvdec_push_data2 · Advisory · strukturag/libheif · GitHub

https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9v
generic

Out-of-Bounds Read in vvdec_push_data2() Due to Missing Length Validation · Issue #1712 · strukturag/libheif · GitHub

https://github.com/strukturag/libheif/issues/1712

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 14× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-28 15:37 UTCEPSS rescore
  2. 2026-07-27 15:23 UTCEG score recompute▼ 0.70
  3. 2026-07-27 15:21 UTCNVD updateCVSS v3 → 6.1
  4. 2026-07-27 09:33 UTCEG score recompute
  5. 2026-07-26 14:54 UTCEPSS rescore
  6. 2026-07-26 09:58 UTCEG score recompute
  7. 2026-07-25 14:18 UTCEPSS rescore
  8. 2026-07-24 14:18 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 03:17 UTCEG score recompute
  11. 2026-07-22 22:56 UTCEG score recompute
  12. 2026-07-22 14:08 UTCEPSS rescore
  13. 2026-07-21 23:11 UTCEG score recompute
  14. 2026-07-21 21:38 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-47251?
CVE-2026-47251 is a medium vulnerability published on July 21, 2026. 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…
When was CVE-2026-47251 disclosed?
CVE-2026-47251 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on July 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47251 actively exploited?
CVE-2026-47251 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 92.2% of all scored CVEs.
What is the CVSS score of CVE-2026-47251?
CVE-2026-47251 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-47251?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47251, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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