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TI-2026-54088 Aliases CVE-2026-77587GHSA-9mf5-x83c-fg2x

Use after free in torproject Tor

Priority LOW 33CWE-911Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.

Summary

Tor before 0.4.9.11 is prone to a use-after-free (and potential double free) of a conflux object when a recovery leg revives a conflux set whose last linked leg has already been closed. A malicious exit node could use this to crash a client. This is TROVE-2026-026.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00405 35th percentileScored 2026-11-07
Fix Fixed Tor (torproject): 0.4.9.11

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
torprojectTor0.4.8.1-alpha to before 0.4.9.110.4.9.11Patch availableCNA
  • Tor Vendortorproject Affected 0.4.8.1-alpha to before 0.4.9.11 Fixed in 0.4.9.11 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*before 0.4.9.11Vulnerabletorproject
  • cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* Versions before 0.4.9.11 Vulnerable ·torproject

Remediation

  • Fix · CNA Tor (torproject) Fixed in 0.4.9.11

Fixed in the same release

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

  • Release ·

    torproject Tor 0.4.9.11

    2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW

    Other records, highest priority first

    Show all 2 records →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-77587
  2. 2026-10-03 Alias added: GHSA-9mf5-x83c-fg2x

References

Advisory 1

  • TI-2016-07433 Use after free in Mozilla Firefox KEVCVSS 3.1HIGH 7.5
  • TI-2023-09419 The SafeSocks option in Tor before 0.4.7.13 has a logic error in which the unsafe SOCKS4… CVSS 3.1MEDIUM 6.5
  • TI-2018-00448 Use after free in Tor CVSS 3.0HIGH 7.5
  • TI-2026-54108 Race condition in torproject Tor CVSS 3.1CRITICAL 9.0
  • TI-2026-54112 Out-of-bounds write in torproject Tor CVSS 3.1CRITICAL 9.3
  • TI-2026-32508 Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell… CVSS 3.1CRITICAL 9.1
See all 47 →

Sources

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