CVE-2026-84448

MEDIUMPre-NVD 4.04.0
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 4.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: secondary
4.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 4.0Exploit: 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. 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.

CVSS v3
4.0
EG Score
4.0(low)
EG Risk
23(Track)
EG Risk 23/100SSVC: 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
Severity40% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 18, 2026

Last Modified

September 18, 2026

Advisory Details (3)

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

v1.23.2 - security release

Patch available: strukturag/libheif v1.23.2

https://github.com/strukturag/libheif/releases/tag/v1.23.2
github_commit Patch Available

commit 646d85fbf5bd (strukturag/libheif)

Patch available: strukturag/libheif v1.23.2 (contains commit 646d85fbf5bd)

https://github.com/strukturag/libheif/commit/646d85fbf5bd18fc3cdc516e915e59072de2d510
github Patch Available🟡 PoC Available

Heap out-of-bounds read in libheif inline-mask region API (heif_region_item_add_region_inline_mask_data / heif_region_get_mask_image) · Advisory · strukturag/libheif · GitHub

https://github.com/strukturag/libheif/security/advisories/GHSA-p58j-h3vm-3fp5

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 3× in last 7d / 3× 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. 2026-09-18 16:25 UTCEG score recompute
  2. 2026-09-18 16:02 UTCEG score recompute
  3. 2026-09-18 15:59 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-84448?
CVE-2026-84448 is a medium vulnerability published on September 18, 2026. libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, the public heifregionitemaddregioninlinemaskdata() function in libheif/api/libheif/heifregions.cc accepts maskdatalen without verifying that it equals the byte count required by width and height. A later…
When was CVE-2026-84448 disclosed?
CVE-2026-84448 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.
What is the CVSS score of CVE-2026-84448?
CVE-2026-84448 has a CVSS v3 base score of 4.0 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-84448?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84448, 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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