CVE-2026-77317Public exploitNetwork attack vector

Cross-tenant file access via literal prefix matching

Published Aug 26, 2026 · Updated Aug 26, 2026

Incorrect authorization in SeaweedFS 3.88 through 4.39 allows remote authenticated users to read or overwrite sibling-tenant files via SFTP. The SFTP permission checks in weed/sftpd/sftp_permissions.go use strings.HasPrefix without requiring an exact path or separator-delimited descendant. Exploitation requires valid low-privilege SFTP credentials, a root home directory, and narrow path permissions; read grants disclosure and write grants modification.

CVSS severity8.1
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in SeaweedFS 3.88 through 4.39 allows remote authenticated users to read or overwrite sibling-tenant files via SFTP. The SFTP permission checks in weed/sftpd/sftp_permissions.go use strings.HasPrefix without requiring an exact path or separator-delimited descendant. Exploitation requires valid low-privilege SFTP credentials, a root home directory, and narrow path permissions; read grants disclosure and write grants modification.

The record

CVE
CVE-2026-77317
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
SeaweedFS
Product
SeaweedFS
Classifications
CWE-863, T1213, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 3.88, < 4.40

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SeaweedFS · SeaweedFSversion=>= 3.88, < 4.40

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1213Data from Information Repositories
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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