CVE-2026-84450

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 67% 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, secondary
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: None knownExposed: 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. From 1.19.0 until 1.23.3, a crafted image item containing a clap property and an ispe width or height greater than INT32_MAX + 1 can reach crop calculations through heif_image_handle_get_image_tiling(). Box_clap::left_rounded() or Box_clap::top_rounded() passes the image dimension minus one to Fraction::Fraction(), whose uint32_t constructor uses an assertion as input validation, causing assert-enabled builds to abort. Release builds can instead compute invalid crop geometry, and the tiling API returns dimensions that the normal decode security limits reject. This issue is fixed in version 1.23.3.

CVSS v3
4.3
EG Score
4.3(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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
Severity43% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

September 18, 2026

Last Modified

September 18, 2026

Advisory Details (3)

Auto-updated Sep 18, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

`clap` + oversized `ispe` aborts on an assert in `Fraction::Fraction` (incomplete fix for GHSA-jc8f-p23p-5hjg) · Advisory · strukturag/libheif · GitHub

https://github.com/strukturag/libheif/security/advisories/GHSA-gh5q-69gg-c964
github_release Patch Available

v1.23.3 - security release

Patch available: strukturag/libheif v1.23.3

https://github.com/strukturag/libheif/releases/tag/v1.23.3
github_commit Patch Available

commit 1c2df9c0e814 (strukturag/libheif)

Patch available: strukturag/libheif v1.23.3 (contains commit 1c2df9c0e814)

https://github.com/strukturag/libheif/commit/1c2df9c0e814f89716f3a4d85a444b2dbc63ad69

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 4× 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. 2026-09-19 17:50 UTCEG score recompute
  2. 2026-09-18 16:25 UTCEG score recompute
  3. 2026-09-18 16:15 UTCEG score recompute
  4. 2026-09-18 16:14 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84450?
CVE-2026-84450 is a medium vulnerability published on September 18, 2026. libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.3, a crafted image item containing a clap property and an ispe width or height greater than INT32MAX + 1 can reach crop calculations through heifimagehandlegetimagetiling(). Boxclap::leftrounded() or…
When was CVE-2026-84450 disclosed?
CVE-2026-84450 was first published in the National Vulnerability Database on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84450 actively exploited?
CVE-2026-84450 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 66.5% of all scored CVEs.
What is the CVSS score of CVE-2026-84450?
CVE-2026-84450 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-84450?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84450, 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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