CVE-2026-77611

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 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 weekElevated
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: Elevated riskExposed: 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 versions prior to 4.40, an authenticated S3 principal with permissions scoped to a nested object key can overwrite a different object outside that scope by calling PutObjectAcl on the key it is allowed to access. The handler authorizes the request against the requested nested key but then writes the updated entry back to the bucket root rather than the key's actual parent directory, so an ACL change on allowed/protected.txt is instead applied to protected.txt at the bucket root. Because the update carries the full entry rather than only ACL metadata, an existing target object is overwritten with the content, metadata, owner information, and ACL of the scoped object, bypassing the object-level action scoping configured through the static S3 identity file. This issue is fixed in version 4.40.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
48(Track)
EG Risk 48/100SSVC: 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
Severity71% × 45%
Exploitation40% × 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 (2)

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

commit 311bc3a6dfbd (seaweedfs/seaweedfs)

Fix landed in seaweedfs/seaweedfs commit 311bc3a6dfbd — awaiting tagged release

https://github.com/seaweedfs/seaweedfs/commit/311bc3a6dfbd042751692bc3de8accc516fcf8c1
github Patch Available🟡 PoC Available

Authenticated S3 object-scope bypass in PutObjectAcl allows overwriting a different object with the same basename · Advisory · seaweedfs/seaweedfs · GitHub

https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-9x53-cjpr-m682

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 9× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 07:20 UTCEG score recompute
  3. 2026-08-28 21:42 UTCEPSS rescore
  4. 2026-08-27 17:30 UTCEG score recompute
  5. 2026-08-27 17:06 UTCEG score recompute
  6. 2026-08-27 14:25 UTCEPSS rescore
  7. 2026-08-26 22:24 UTCEG score recompute
  8. 2026-08-26 22:02 UTCEG score recompute
  9. 2026-08-26 22:01 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77611?
CVE-2026-77611 is a high vulnerability published on August 26, 2026. SeaweedFS is a distributed storage system for files and blobs. In versions prior to 4.40, an authenticated S3 principal with permissions scoped to a nested object key can overwrite a different object outside that scope by calling PutObjectAcl on the key it is allowed to access. The handler…
When was CVE-2026-77611 disclosed?
CVE-2026-77611 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-2026-77611 actively exploited?
CVE-2026-77611 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 87.5% of all scored CVEs.
What is the CVSS score of CVE-2026-77611?
CVE-2026-77611 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-77611?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77611, 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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