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TI-2026-85166 Aliases CVE-2026-121969GHSA-2v39-q9qf-3m9g

netrek-client-cow Stack Buffer Overflow via handleSMessage

Priority LOW 31CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

netrek-client-cow through 3.3.3 contains a stack-based buffer overflow in handleSMessage() in short.c. A malicious Netrek server, or a man-in-the-middle on the plaintext TCP connection, can send oversized or unterminated SP_S_MESSAGE packets that overflow a 100-byte stack buffer and write server-controlled bytes onto the stack. An attacker with a network position on the connection can crash the client, and user interaction is required.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00344 28th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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
quozlnetrek-client-cowup to 3.3.3—No fix listedCNA
  • netrek-client-cow Vendorquozl Affected up to 3.3.3 Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for netrek-client-cow.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-11-04 Threatist record created from CVE-2026-121969
  2. 2026-11-04 Alias added: GHSA-2v39-q9qf-3m9g
  3. 2026-11-05 CISA SSVC decision points changed
  4. 2026-11-05 Priority changed: MEDIUM → LOW
  5. 2026-11-06 Affected versions changed · Red Hat
  6. 2026-11-06 CVSS score added · Red Hat

References

Patch 1

Other 3

  • TI-2026-85165 Out-of-bounds read in netrek-client-cow lets servers crash clients CVSS 4.0HIGH 7.1

Sources

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