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TI-2026-80205 Aliases CVE-2026-116187GHSA-8qg9-895h-w83f

Authorization bypass in Rclone serve s3 multipart uploads

Priority LOW 26CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
High · Low · Low
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-639.

Summary

Rclone from 1.68.0 before 1.75.2 is affected. Its serve s3 auth proxy mode does not check that an authenticated tenant owns the multipart upload ID it references, which is an authorization bypass through a user-controlled key (CWE-639). A tenant who learns another tenant's bucket, object and upload ID can add parts to, complete or abort that upload and view upload and object metadata.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Rclone from v1.68.0 before v1.75.2 contains an authorization bypass vulnerability in serve s3 --auth-proxy that allows authenticated tenants to manipulate other tenants' multipart uploads by referencing their upload IDs. Attackers who learn a victim's bucket, object, and upload ID can inject parts, complete, or abort in-flight uploads and view upload and object metadata across tenants.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00143 3rd percentileScored 2026-11-07
Fix Partial rclone (rclone): 1.75.2Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rclonerclone1.68.0 to before 1.75.21.75.2Patch availableCNA
  • rclone Vendorrclone Affected 1.68.0 to before 1.75.2 Fixed in 1.75.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:rclone:rclone:*:*:*:*:*:*:*:*1.68.0 to before 1.75.2Vulnerablerclone
  • cpe:2.3:a:rclone:rclone:*:*:*:*:*:*:*:* Versions 1.68.0 to before 1.75.2 Vulnerable ·rclone

Remediation

Upgrade rclone to version 1.75.2, the fixed version. Red Hat lists Cryostat 4 and Red Hat Advanced Cluster Management for Kubernetes 2 as affected without a fix and with no plan available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA rclone (rclone) Fixed in 1.75.2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    rclone 1.75.2

    9 records Highest priority Priority HIGH 4 HIGH, 2 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-80211 Authentication bypass in rclone serve webdav via OPTIONS requestsPriority HIGH 70
    • TI-2026-80206 Integer overflow in rclone serve s3 lets attackers exhaust memoryPriority HIGH 70
    • TI-2026-80207 Signature verification bypass in rclone selfupdatePriority HIGH 69
    Show all 9 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Cryostat 4AffectedNo fix yet: Fix deferred
Red Hat Advanced Cluster Management for Kubernetes 2AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-25 Threatist record created from CVE-2026-116187
  2. 2026-10-26 Affected versions changed · Red Hat
  3. 2026-10-26 CVSS score added · Red Hat
  4. 2026-10-26 CISA SSVC decision points changed
  5. 2026-10-26 Priority changed: MEDIUM → LOW
  6. 2026-10-27 Alias added: GHSA-8qg9-895h-w83f

References

Advisory 1

  • TI-2026-60044 rclone serve s3: --auth-proxy without --auth-key authenticates nobody - full SigV4 signature bypass CVSS 3.1CRITICAL 9.8
  • TI-2026-29802 RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution CVSS 4.0CRITICAL 9.2
  • TI-2026-29799 Rclone: Unauthenticated options/set allows runtime auth bypass, leading to sensitive operations and command execution CVSS 4.0CRITICAL 9.2
  • TI-2026-42602 Path traversal in rclone CVSS 3.1HIGH 8.8
  • TI-2026-39407 rclone: Unvalidated symlink target in local `--links` — arbitrary file write from an untrusted remote CVSS 3.1HIGH 8.8
  • TI-2026-80211 Authentication bypass in rclone serve webdav via OPTIONS requests CVSS 4.0MEDIUM 6.9
See all 23 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences