What is CVE-2026-87724?

CVE-2026-87724 is a medium-severity vulnerability in Torprject Tor, classified under Incorrect Resource Transfer Between Spheres. CVSS score: 6.5/10. Published 2026-09-09.

How severe is CVE-2026-87724?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Torprject Tor

CVE-2026-87724

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.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H.

Affected products

Torprject Tor

Weakness classification (CWE)

CWE-669 — Incorrect Resource Transfer Between Spheres

References

cve@mitre.org
cve@mitre.org

Frequently asked questions

What is CVE-2026-87724?: CVE-2026-87724 is a medium-severity vulnerability in Torprject Tor, classified under Incorrect Resource Transfer Between Spheres. CVSS score: 6.5/10. Published 2026-09-09.
How severe is CVE-2026-87724?: Medium severity. CVSS v3 base score is 6.5 out of 10.