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TI-2026-80957 Aliases CVE-2026-116748GHSA-jw4h-7968-5hj9

Permissive CORS in Transmission exposes RPC anti-CSRF token

Priority MEDIUM 42CWE-942Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Transmission from 4.0.0 before 4.1.3 has a permissive CORS policy in its RPC server that exposes the X-Transmission-Session-Id anti-CSRF token to any web origin. A malicious web page can read the token from the 409 handshake response and replay it to issue RPC calls. An unauthenticated remote attacker who lures a user to a crafted page can change download directories, run script-torrent-done actions, or delete torrents and data. The weakness is classified as CWE-942.

Written with Claude Haiku 5.5 from the sources below · 2026-10-31

Description from the CNA

Transmission 4.0.0 before 4.1.3 contains a permissive CORS vulnerability in handle_request() in rpc-server.cc that exposes the X-Transmission-Session-Id anti-CSRF token to any web origin. Malicious web pages can read the token from the 409 handshake response and replay it to issue RPC calls, enabling script-torrent-done execution, download-dir changes, or torrent and data deletion.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01246 69th percentileScored 2026-11-07
Fix Fixed transmission (transmission): 4.1.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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

Affected products

VendorProductAffected versionsFixed inStatusSource
transmissiontransmission4.0.0 to before 4.1.34.1.3Patch availableCNA
  • transmission Vendortransmission Affected 4.0.0 to before 4.1.3 Fixed in 4.1.3 Patch available CNA

Remediation

Update Transmission to version 4.1.3 or later. Red Hat lists one product as not affected.

Written with Claude Haiku 5.5 from the sources below · 2026-10-31

  • Fix · CNA transmission (transmission) Fixed in 4.1.3

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-26 Threatist record created from CVE-2026-116748
  2. 2026-10-27 Affected versions changed · Red Hat
  3. 2026-10-27 CVSS score added · Red Hat
  4. 2026-10-27 Alias added: GHSA-jw4h-7968-5hj9
  5. 2026-10-27 Priority changed: MEDIUM → LOW
  6. 2026-10-30 EPSS moved to the 50th–90th percentile
  7. 2026-10-31 Priority changed: LOW → MEDIUM
  8. 2026-10-31 CISA SSVC decision points changed

References

Patch 2

Advisory 1

Other 3

Sources

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