PatchTheCVECVE-2026-77587: Tor before 0.4.9.11 is prone to a use-after-free (and potential double free) of a conflux object when a recove
CVE-2026-77587 is a medium-severity flaw (CVSS 5.9) affecting tor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Last updated 2026-10-18 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-77587?
tor: upgrade to 0.4.9.11. Exact commands for each OS are on this page.
Is CVE-2026-77587 being exploited?
CVE-2026-77587 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-77587 affect?
CVE-2026-77587 affects tor. Severity is medium (CVSS 5.9). 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
How urgent is CVE-2026-77587?
Priority 34/100. Remotely exploitable, no login, no user action
Related CVEs
- CVE-2026-44603 LOW 3.7 UPGRADE Tor before 0.4.9.7 has an out-of-bounds read by one byte via a malformed BEGIN cell, aka TROVE-2026-007.
- CVE-2026-44597 LOW 3.7 UPGRADE Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell lacks a reason in it
- CVE-2026-44600 LOW 3.7 UPGRADE Tor before 0.4.9.7 mishandles accounting of the conflux out-of-order queue during the clearing of a queue, aka
- CVE-2026-44601 LOW 3.7 UPGRADE Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a doub
- CVE-2026-44602 LOW 3.7 UPGRADE Tor before 0.4.9.7 has a NULL pointer dereference when a CERT cell is received out of order, aka TROVE-2026-00