mport is the MidnightBSD Package Manager. Prior to 2.7.8, libmport/util.c did not make every truncated, corrupt, or failed zstd stream fatal in mport_decompress_zstd(), and libmport/fetch.c did not consistently propagate those failures to index-fetch callers. A malicious or faulty mirror could supply compressed package index data that caused ZSTD_decompressStream() or an output write to fail while leaving partial index output available for later use, resulting in package-index integrity loss or denial of service. This issue is fixed in version 2.7.8.
CVE-2026-54580
HIGHPre-NVD 8.38.3—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 83% of all CVEs by exploit prediction. 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: epss, secondary
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.3Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.3
- EG Score
- 8.3(medium)
- EG Risk
- 42(Track)EG Risk 42/100SSVC: 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 computedSeverity83% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 17%
- KEV
- Not listed
Published
September 17, 2026
Last Modified
September 17, 2026
Advisory Details (4)
Auto-updated Sep 17, 2026Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available
mport 2.7.8
Patch available: MidnightBSD/mport 2.7.8
https://github.com/MidnightBSD/mport/releases/tag/2.7.8github_commit Patch Available
commit b3e11ba07835 (MidnightBSD/mport)
Patch available: MidnightBSD/mport 2.7.8 (contains commit b3e11ba07835)
https://github.com/MidnightBSD/mport/commit/b3e11ba078351402082a881209ee6fda5d332e3dgithub_pr Patch Available
Harden zstd decompression and propagate failures to index fetch
Patch available: MidnightBSD/mport 2.7.8 (PR #135 merged 2026-05-15)
https://github.com/MidnightBSD/mport/pull/135github Patch Available
mport index decompression can leave partial or corrupt index data after zstd failures · Advisory · MidnightBSD/mport · GitHub
Affected: 2.7.8
https://github.com/MidnightBSD/mport/security/advisories/GHSA-ffqj-j42r-747wWeakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× 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.
- 2026-09-18 19:51 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-17 17:35 UTCEG score recompute
- 2026-09-17 17:00 UTCEG score recompute
- 2026-09-17 16:59 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-54580?
CVE-2026-54580 is a high vulnerability published on September 17, 2026. mport is the MidnightBSD Package Manager. Prior to 2.7.8, libmport/util.c did not make every truncated, corrupt, or failed zstd stream fatal in mportdecompresszstd(), and libmport/fetch.c did not consistently propagate those failures to index-fetch callers. A malicious or faulty mirror could supply…
When was CVE-2026-54580 disclosed?
CVE-2026-54580 was first published in the National Vulnerability Database on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54580 actively exploited?
CVE-2026-54580 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 83.3% of all scored CVEs.
What is the CVSS score of CVE-2026-54580?
CVE-2026-54580 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-54580?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54580, 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-2026-54580
Is Your Infrastructure Affected by CVE-2026-54580?
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