CVE-2026-77368

HIGHPre-NVD 7.67.6—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 88% 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
Trending — 3 sources updated this week
7.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.6Exploit: None knownExposed: 0

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

SeaweedFS is a distributed storage system for files and blobs. In version 4.39, the filer's TUS resumable-upload handler checks JWT allowed_prefixes scoping only when a session is created, letting a low-privilege tenant hijack another tenant's upload session to write content to filer paths their own token forbids. The HEAD, PATCH, and DELETE verbs that act on an existing session by its id never verify that the session's stored target path falls within the caller's allowed prefixes, so a tenant who obtains another upload's session identifier can PATCH attacker bytes into it and, on completion, have the file land at the victim's out-of-scope path. The same token can also DELETE other tenants' sessions and HEAD them to read upload progress and size, defeating the JWT prefix isolation. This vulnerability only affects deployments that configure filer JWT signing and have TUS uploads enabled. This issue is fixed in version 4.40.

CVSS v3
7.6
EG Score
7.6(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: 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
Severity76% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

August 26, 2026

Last Modified

August 27, 2026

Advisory Details (3)

Auto-updated Aug 26, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit

commit fa549e9c83b7 (seaweedfs/seaweedfs)

Fix landed in seaweedfs/seaweedfs commit fa549e9c83b7 — awaiting tagged release

https://github.com/seaweedfs/seaweedfs/commit/fa549e9c83b7799d512157d728f52052912831af
github_commit

commit ce82e3a05708 (seaweedfs/seaweedfs)

Fix landed in seaweedfs/seaweedfs commit ce82e3a05708 — awaiting tagged release

https://github.com/seaweedfs/seaweedfs/commit/ce82e3a057080162a9fba11889157d2255815f71
github Patch Available🟡 PoC Available

Authenticated Cross-Prefix IDOR in SeaweedFS Filer TUS Handler Enables Arbitrary Write to Tenant-Forbidden Paths · Advisory · seaweedfs/seaweedfs · GitHub

https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-99q7-x53r-6j4g

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 6× 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. 2026-08-27 17:30 UTCEG score recompute
  2. 2026-08-27 17:07 UTCEG score recompute
  3. 2026-08-27 14:25 UTCEPSS rescore
  4. 2026-08-26 22:24 UTCEG score recompute
  5. 2026-08-26 22:02 UTCEG score recompute
  6. 2026-08-26 22:01 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77368?
CVE-2026-77368 is a high vulnerability published on August 26, 2026. SeaweedFS is a distributed storage system for files and blobs. In version 4.39, the filer's TUS resumable-upload handler checks JWT allowed_prefixes scoping only when a session is created, letting a low-privilege tenant hijack another tenant's upload session to write content to filer paths their…
When was CVE-2026-77368 disclosed?
CVE-2026-77368 was first published in the National Vulnerability Database on August 26, 2026, with the most recent update on August 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77368 actively exploited?
CVE-2026-77368 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 88.2% of all scored CVEs.
What is the CVSS score of CVE-2026-77368?
CVE-2026-77368 has a CVSS v3 base score of 7.6 (NVD).
How do I remediate CVE-2026-77368?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77368, 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

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