Public proof of conceptFix available

CVE-2026-77317

Q: Is CVE-2026-77317 actively exploited?

A proof-of-concept exploit exists for CVE-2026-77317, but active exploitation has not been confirmed at this time.

Q: What is the CVSS score for CVE-2026-77317?

CVE-2026-77317 has a CVSS v3 base score of 8.1 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

SeaweedFS: SFTP path ACL literal prefix match permits cross-tenant file read and overwrite

A public proof of concept exists; no exploitation attested.

Published2026-08-26
Fixed in4.40.0
WeaknessCWE-863

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

SeaweedFS is a distributed storage system for files and blobs. In versions from 3.88 through 4.39, the SFTP server evaluates configured path permissions with a literal string-prefix comparison, so a user scoped to a path is also granted the same access to any sibling path whose name merely begins with the same characters. A user granted access to /tenants/alice therefore also matches /tenants/alice-archive, /tenants/alice2, and similar siblings, because the check does not require a path-component boundary. An authenticated low-privilege SFTP user with a root home directory and narrow path permissions can thereby cross the configured ACL boundary to read another tenant's files, and to overwrite them if granted write, all through the documented SFTP service with its own valid credentials. This issue is fixed in version 4.40.

Timeline

dates in UTC

2026-08-2622:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-30 15:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-77317?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-77317?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV

seaweedfs

Branch	Affected	Fixed in	Source
4.40	≥ 3.88.0, < 4.40.0	4.40.0	OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update seaweedfs to 4.40.0

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionpoc2026-08-29
OpenCVESSVC decisionpoc—
CNACVSS 3.18.1read 2026-10-23
CNAweakness (CWE)CWE-863read 2026-10-23
FIRST EPSSEPSS score0.4 %2026-10-29
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Published: 2026-08-26
Last Modified: 2026-09-09
NVD status: Deferred

Frequently asked questions

What is CVE-2026-77317?

Is CVE-2026-77317 actively exploited?

A proof-of-concept exploit exists for CVE-2026-77317, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-77317?

CVE-2026-77317 has a CVSS v3 base score of 8.1 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

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