CVE-2026-84448

MEDIUMPre-NVD 4.04.0
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 4.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (8th 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
Elevated

Also known asEUVD-2026-83015 (ENISA EUVD)Source: ENISA EUVD

4.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.0Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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
4.0MEDIUMmedium confidence
EG Risk
34
EG Risk 34/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity40% × 45%
Impact severity (EG Severity): CVSS 4.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (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
0.2%
EPSS %ILE
8th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (4.0): severity, escalated by confirmed exploitation. This CVE's 4.0 is its impact severity (EG Severity), not escalated.

EG Severity
4.0 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation public PoC (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.

The score's inputs: 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, 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 advisoryMentions a patch (unverified)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibheif1 (1.1.0-2ubuntu0.1~esm5) @ bionic2026-10-12ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

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 ... 1.23.1-1 (9 versions)
  • every version up to 1.23.2-1: fixed in 1.23.2-1
—

Weakness Classification(2)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× in last 7d / 54× 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. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  4. 2026-10-30 00:55 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  10. 2026-10-25 13:56 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  14. 2026-10-22 13:00 UTCEG score recompute
  15. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  18. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  19. 2026-10-18 03:06 UTCEG score recompute
  20. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  22. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  23. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  24. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  25. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
Show 59 more
  1. 2026-10-12 14:53 UTCEG score recompute
  2. 2026-10-12 04:57 UTCVendor advisory
  3. 2026-10-11 19:18 UTCEG score recompute
  4. 2026-10-11 16:35 UTCEG score recompute
  5. 2026-10-11 13:52 UTCEG score recompute
  6. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  7. 2026-10-11 02:47 UTCEG score recompute
  8. 2026-10-11 02:47 UTCVendor advisory
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  10. 2026-10-10 00:45 UTCEG score recompute
  11. 2026-10-10 00:45 UTCVendor advisory
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  13. 2026-10-08 22:49 UTCEG score recompute
  14. 2026-10-08 22:49 UTCVendor advisory
  15. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  17. 2026-10-07 20:54 UTCVendor advisory
  18. 2026-10-06 18:50 UTCEG score recompute
  19. 2026-10-06 18:50 UTCVendor advisory
  20. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  21. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  22. 2026-10-05 16:55 UTCEG score recompute
  23. 2026-10-05 16:55 UTCVendor advisory
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  25. 2026-10-04 15:00 UTCEG score recompute
  26. 2026-10-04 15:00 UTCVendor advisory
  27. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  28. 2026-10-03 13:04 UTCEG score recompute
  29. 2026-10-03 13:04 UTCVendor advisory
  30. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  31. 2026-10-02 11:06 UTCEG score recompute
  32. 2026-10-02 11:06 UTCVendor advisory
  33. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  34. 2026-10-01 09:11 UTCEG score recompute
  35. 2026-10-01 09:11 UTCVendor advisory
  36. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  37. 2026-09-30 07:17 UTCEG score recompute
  38. 2026-09-30 07:17 UTCVendor advisory
  39. 2026-09-29 05:21 UTCEG score recompute
  40. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  41. 2026-09-28 03:26 UTCEG score recompute
  42. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  43. 2026-09-27 01:32 UTCEG score recompute
  44. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  45. 2026-09-25 23:35 UTCEG score recompute
  46. 2026-09-24 21:24 UTCEG score recompute
  47. 2026-09-24 21:12 UTCEG score recompute
  48. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  49. 2026-09-24 02:00 UTCEG score recompute
  50. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  51. 2026-09-23 00:05 UTCEG score recompute
  52. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  53. 2026-09-21 22:09 UTCEG score recompute
  54. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  55. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  56. 2026-09-19 18:20 UTCEG score recompute
  57. 2026-09-18 16:25 UTCEG score recompute
  58. 2026-09-18 16:02 UTCEG score recomputeFirst assessed: 4.0 MEDIUM
  59. 2026-09-18 15:59 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-84448?
CVE-2026-84448 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. 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…
When was the CVE record for CVE-2026-84448 published?
The CVE record for CVE-2026-84448 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-2026-84448 actively exploited?
CVE-2026-84448 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-84448?
CVE-2026-84448 has a CVSS base score of 4.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-84448?
A fix for CVE-2026-84448 is available: update to the fixed version the vendor names in its advisory.

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