CVE-2026-21091

HIGHNVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory published 2026-09-09. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

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

Out-of-bounds write in libcodec2secevrcdec.so prior to SMR Sep-2026 Release 1 allows local attackers to write out-of-bounds memory.

CVSS v3
7.8
EG Score
7.8(high)
EG Risk
35(Track)
EG Risk 35/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
1%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 11, 2026

Advisory Details (1)

Auto-updated Sep 9, 2026
No patch confirmed yet.
generic

Samsung Mobile Security

https://security.samsungmobile.com/securityUpdate.smsb?year=2026&month=09

Vendor Advisories for CVE-2026-21091(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 24× in last 7d / 66× 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. 2026-09-25 07:12 UTCGHSA enrichment
  2. 2026-09-24 20:18 UTCEG score recompute
  3. 2026-09-24 20:18 UTCGHSA enrichment
  4. 2026-09-24 14:03 UTCEPSS rescore
  5. 2026-09-24 09:21 UTCGHSA enrichment
  6. 2026-09-23 22:27 UTCEG score recompute
  7. 2026-09-23 22:27 UTCGHSA enrichment
  8. 2026-09-23 11:33 UTCGHSA enrichment
  9. 2026-09-23 00:39 UTCEG score recompute
  10. 2026-09-23 00:39 UTCGHSA enrichment
  11. 2026-09-22 13:44 UTCGHSA enrichment
  12. 2026-09-22 02:50 UTCEG score recompute
  13. 2026-09-22 02:50 UTCGHSA enrichment
  14. 2026-09-21 15:55 UTCGHSA enrichment
  15. 2026-09-21 05:01 UTCEG score recompute
  16. 2026-09-21 05:00 UTCGHSA enrichment
  17. 2026-09-20 20:15 UTCEPSS rescore
  18. 2026-09-20 18:05 UTCGHSA enrichment
  19. 2026-09-20 07:03 UTCGHSA enrichment
  20. 2026-09-19 19:36 UTCGHSA enrichment
  21. 2026-09-19 08:41 UTCGHSA enrichment
  22. 2026-09-18 21:43 UTCEG score recompute
  23. 2026-09-18 21:43 UTCGHSA enrichment
  24. 2026-09-18 19:27 UTCEPSS rescore
  25. 2026-09-18 10:49 UTCGHSA enrichment
Show 41 more
  1. 2026-09-17 23:55 UTCEG score recompute
  2. 2026-09-17 23:55 UTCGHSA enrichment
  3. 2026-09-17 11:45 UTCGHSA enrichment
  4. 2026-09-17 00:51 UTCEG score recompute
  5. 2026-09-17 00:51 UTCGHSA enrichment
  6. 2026-09-16 14:07 UTCEPSS rescore
  7. 2026-09-16 13:57 UTCEG score recompute
  8. 2026-09-16 13:57 UTCGHSA enrichment
  9. 2026-09-16 05:15 UTCEPSS rescore
  10. 2026-09-16 03:03 UTCGHSA enrichment
  11. 2026-09-15 16:09 UTCGHSA enrichment
  12. 2026-09-15 05:15 UTCEG score recompute
  13. 2026-09-15 05:14 UTCGHSA enrichment
  14. 2026-09-14 18:16 UTCGHSA enrichment
  15. 2026-09-14 06:30 UTCGHSA enrichment
  16. 2026-09-13 19:36 UTCEG score recompute
  17. 2026-09-13 19:36 UTCGHSA enrichment
  18. 2026-09-13 16:47 UTCEPSS rescore
  19. 2026-09-13 08:42 UTCGHSA enrichment
  20. 2026-09-12 21:48 UTCEG score recompute
  21. 2026-09-12 21:48 UTCGHSA enrichment
  22. 2026-09-12 15:01 UTCEPSS rescore
  23. 2026-09-12 10:53 UTCGHSA enrichment
  24. 2026-09-11 23:57 UTCEG score recompute
  25. 2026-09-11 23:57 UTCGHSA enrichment
  26. 2026-09-11 14:52 UTCEPSS rescore
  27. 2026-09-11 13:03 UTCEG score recompute▲ 3.00
  28. 2026-09-11 13:03 UTCGHSA enrichment
  29. 2026-09-11 13:02 UTCNVD updateCVSS v3 → 7.8 · severity → HIGH
  30. 2026-09-10 15:23 UTCEG score recompute▲ 0.40
  31. 2026-09-10 15:23 UTCGHSA enrichment
  32. 2026-09-10 15:19 UTCNVD updateCVSS v3 → 4.8 · CVSS v4 → 4.8
  33. 2026-09-10 14:36 UTCEG score recompute▼ 0.40
  34. 2026-09-10 14:36 UTCGHSA enrichment
  35. 2026-09-10 14:35 UTCMITRE cvelistV5CVSS v3 → 4.4 · CVSS v4 → 4.4
  36. 2026-09-10 09:34 UTCEPSS rescore
  37. 2026-09-09 15:50 UTCGHSA enrichment
  38. 2026-09-09 05:25 UTCEG score recompute▲ 0.40
  39. 2026-09-09 05:24 UTCNVD updateCVSS v3 → 4.8 · CVSS v4 → 4.8
  40. 2026-09-09 04:55 UTCEG score recompute
  41. 2026-09-09 04:55 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21091?
CVE-2026-21091 is a high vulnerability published on September 9, 2026. Out-of-bounds write in libcodec2secevrcdec.so prior to SMR Sep-2026 Release 1 allows local attackers to write out-of-bounds memory.
When was CVE-2026-21091 disclosed?
CVE-2026-21091 was first published in the National Vulnerability Database on September 9, 2026, with the most recent update on September 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21091 actively exploited?
CVE-2026-21091 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 99.0% of all scored CVEs.
What is the CVSS score of CVE-2026-21091?
CVE-2026-21091 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-21091?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21091, 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

Explore the affected products and dependency analysis for CVE-2026-21091

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