CVE-2026-88386

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH confidence

Score 5.5 from GitHub Security Advisory published 2026-09-24. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.5Exploit: Elevated riskExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

libsndfile 1.2.2 contains a misaligned memory access issue in psf_binheader_readf() while parsing WAV fmt chunks. A specially crafted WAV file can cause the function to cast an unaligned destination address to unsigned int * and perform a 4-byte store. This results in undefined behavior leading to denial of service.

CVSS v3
5.5
EG Score
5.5MEDIUMhigh confidence
EG Risk
41
EG Risk 41/100CISA SSVC

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
Severity55% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
EPSS PROB
0.1%
EPSS %ILE
below the 1st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 24, 2026

Last Modified

September 25, 2026

Advisory Details (2)

Auto-updated Sep 25, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit 474e4d328b1e (mhlavink/libsndfileci)

Fix landed in mhlavink/libsndfileci commit 474e4d328b1e — awaiting tagged release

https://github.com/mhlavink/libsndfileci/commit/474e4d328b1e6240b93ec6ed14efb7c6a44bee57
generic

[Bug]misaligned 4-byte store in psf_binheader_readf while parsing a crafted WAV 'fmt ' chunk (CWE-704) · Issue #1150 · libsndfile/libsndfile · GitHub

https://github.com/libsndfile/libsndfile/issues/1150

Vendor Advisories for CVE-2026-88386(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 18× in last 7d / 30× 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. 2026-10-04 09:48 UTCEG score recompute
  2. 2026-10-04 09:48 UTCGHSA enrichment
  3. 2026-10-03 10:42 UTCEG score recompute
  4. 2026-10-03 10:42 UTCGHSA enrichment
  5. 2026-10-02 11:36 UTCEG score recompute
  6. 2026-10-02 11:36 UTCGHSA enrichment
  7. 2026-10-01 19:51 UTCEPSS rescore
  8. 2026-10-01 12:23 UTCEG score recompute
  9. 2026-10-01 12:23 UTCGHSA enrichment
  10. 2026-09-30 15:04 UTCEPSS rescore
  11. 2026-09-30 13:14 UTCEG score recompute
  12. 2026-09-30 13:14 UTCGHSA enrichment
  13. 2026-09-29 14:08 UTCEG score recompute
  14. 2026-09-29 14:08 UTCGHSA enrichment
  15. 2026-09-28 15:03 UTCGHSA enrichment
  16. 2026-09-27 15:53 UTCEG score recompute
  17. 2026-09-27 15:53 UTCGHSA enrichment
  18. 2026-09-27 13:48 UTCEPSS rescore
  19. 2026-09-26 16:49 UTCEG score recompute
  20. 2026-09-26 16:49 UTCGHSA enrichment
  21. 2026-09-26 15:59 UTCEPSS rescore
  22. 2026-09-25 17:44 UTCEG score recompute
  23. 2026-09-25 17:44 UTCGHSA enrichment
  24. 2026-09-25 16:54 UTCEG score recompute▲ 5.50
  25. 2026-09-25 16:54 UTCGHSA enrichment
Show 5 more
  1. 2026-09-25 16:54 UTCMITRE cvelistV5CVSS v3 → 5.5 · severity → MEDIUM
  2. 2026-09-24 21:37 UTCGHSA enrichment
  3. 2026-09-24 21:22 UTCNVD update
  4. 2026-09-24 20:47 UTCEG score recompute
  5. 2026-09-24 20:47 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88386?
CVE-2026-88386 is a medium vulnerability published on September 24, 2026. libsndfile 1.2.2 contains a misaligned memory access issue in psfbinheaderreadf() while parsing WAV fmt chunks. A specially crafted WAV file can cause the function to cast an unaligned destination address to unsigned int * and perform a 4-byte store. This results in undefined behavior leading to…
When was CVE-2026-88386 disclosed?
CVE-2026-88386 was first published on September 24, 2026, with the most recent update on September 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88386 actively exploited?
CVE-2026-88386 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (below the 1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88386?
CVE-2026-88386 has a CVSS v3.1 base score of 5.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-88386?
An upstream fix for CVE-2026-88386 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-88386 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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