CVE-2026-77584 — HIGH (7.0)

Vulnerability Description

Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the same circuit, attaching an exit stream that would later end up orphan leaving a dangling circuit back-pointer and a use-after-free (UAF) when the circuit is freed. This is TROVE-2026-025.

CVSS Score

7.0

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

LOW

Integrity

HIGH

Availability

LOW

Related Weaknesses (CWE)

CWE-821

References

https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.10/ChangeLog

FAQ

What is CVE-2026-77584?

CVE-2026-77584 is a vulnerability with a CVSS score of 7.0 (HIGH). Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the ...

How severe is CVE-2026-77584?

CVE-2026-77584 has been rated HIGH with a CVSS base score of 7.0/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-77584?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.