CVE-2026-87724

EUVD-2026-74539
Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state. This is TROVE-2026-032.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 36.09%
Debian logo
Debian Releases
Debian Product
Codename
tor
bookworm
vulnerable
bookworm (security)
vulnerable
forky
0.4.9.14-1
fixed
sid
0.4.9.14-1
fixed
trixie
vulnerable
trixie (security)
0.4.9.14-0+deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
tor
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
resolute
needs-triage
trusty
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://gitlab.com/torproject/tor/-/commit/10d4b8ffefa7c00aab2b631ed7e7f15e42cd012d
https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.12/ChangeLog