CVE-2026-84451

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (22nd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.3, the no-icef full-item branch of unc_decoder::get_compressed_image_data_uncompressed() in libheif/codecs/uncompressed/unc_decoder.cc retains an addition-based range check that can wrap when a crafted uncompressed tile grid produces a large range_start_offset and range_size. The overflow makes the bounds comparison pass and allows heif_image_handle_decode_image_tile() to call memcpy() with an invalid source pointer and a very large length when decoding a valid high-index advertised tile. This incomplete remediation of CVE-2026-62292 can reliably crash tile-processing applications, while whole-image decoding is not claimed to reach the demonstrated path. This issue is fixed in version 1.23.3.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

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 (value × EchelonGraph’s weight)
Severity65% × 45%
The EG Score, 6.5 of 10.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
22nd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 18, 2026

Last Modified

September 24, 2026

Advisory Details (3)

Auto-updated Sep 18, 2026
Patch available. Sources: github_commit, github_release, github.
GitHub advisoryMentions a patch (unverified)

Incomplete fix for GHSA-73p7-m7gg-w2jv leaves libheif 1.23.1 vulnerable to an out-of-bounds read · Advisory · strukturag/libheif · GitHub

https://github.com/strukturag/libheif/security/advisories/GHSA-hh47-fhqr-cj2r
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 8bfed9a9ed00 (strukturag/libheif)

Patch available: strukturag/libheif v1.23.3 (contains commit 8bfed9a9ed00)

https://github.com/strukturag/libheif/commit/8bfed9a9ed008e4ef28abc736284a90d3cba754f

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
libheif1.15.1-1 ... 1.23.4-1~deb13u1 (37 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
libheif1.19.8-1 ... 1.23.3-1 (12 versions)
  • every version up to 1.23.4-1~deb13u1: fixed in 1.23.4-1~deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libheif1.19.8-1 ... 1.23.2-1 (10 versions)
  • every version up to 1.23.3-1: fixed in 1.23.3-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 49× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-12 14:53 UTCEG score recompute
  4. 2026-10-11 19:18 UTCEG score recompute
  5. 2026-10-11 16:35 UTCEG score recompute
  6. 2026-10-11 13:52 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-10-11 04:21 UTCEG score recompute
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-10 02:20 UTCEG score recompute
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-09 00:20 UTCEG score recompute
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  15. 2026-10-06 20:19 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  17. 2026-10-05 18:16 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  20. 2026-10-04 16:16 UTCEG score recompute
  21. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  22. 2026-10-03 14:16 UTCEG score recompute
  23. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  24. 2026-10-02 12:16 UTCEG score recompute
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 21st percentile
Show 24 more
  1. 2026-10-01 09:44 UTCEG score recompute
  2. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-09-30 07:44 UTCEG score recompute
  4. 2026-09-29 05:42 UTCEG score recompute
  5. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  6. 2026-09-28 03:41 UTCEG score recompute
  7. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  8. 2026-09-27 01:38 UTCEG score recompute
  9. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-09-24 21:24 UTCEG score recompute
  11. 2026-09-24 21:12 UTCEG score recompute
  12. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  13. 2026-09-24 02:28 UTCEG score recompute
  14. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  15. 2026-09-23 00:28 UTCEG score recompute
  16. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  17. 2026-09-21 22:28 UTCEG score recompute
  18. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  19. 2026-09-20 20:26 UTCEG score recompute
  20. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  21. 2026-09-19 18:25 UTCEG score recompute
  22. 2026-09-18 16:25 UTCEG score recompute
  23. 2026-09-18 16:16 UTCEG score recomputeFirst assessed: 6.5 MEDIUM
  24. 2026-09-18 16:14 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-84451?
CVE-2026-84451 is a medium-severity vulnerability; its CVE record was published on September 18, 2026. libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.3, the no-icef full-item branch of uncdecoder::getcompressedimagedatauncompressed() in libheif/codecs/uncompressed/uncdecoder.cc retains an addition-based range check that can wrap when a crafted uncompressed tile…
When was the CVE record for CVE-2026-84451 published?
The CVE record for CVE-2026-84451 was published on September 18, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 24, 2026; the record at its source may have been updated since.
Is CVE-2026-84451 actively exploited?
CVE-2026-84451 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-84451?
CVE-2026-84451 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-84451?
A fix for CVE-2026-84451 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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