Tor 0.4.7.x before 0.4.7.8 allows a denial of service via the wedging of RTT estimation.

published 2022-07-17 4 y ago modified 2026-06-17 4 mo ago also EUVD-2022-36940

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 71%
public exploits: 0; none known

Patch / fix

fixed in 1 distros 3 links 1

torproject tor 0.4.7.8

debian opensuse alpine

tor Debian 14, Debian 13, Debian 12 0.4.7.8-1

debian advisories DEBIAN-CVE-2022-33903

tor openSUSE Tumbleweed 0.4.7.8-1.1
tor Package Hub 15 SP4, Package Hub 15 SP3, openSUSE Leap 15.4 +1 more 0.4.7.8-bp154.2.3.1

opensuse advisories openSUSE-SU-2024:12149-1 openSUSE-SU-2022:10023-1

tor Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 0.4.7.8-r0

alpine advisories ALPINE-CVE-2022-33903

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

lists.torproject.org/pipermail/tor-announce/2022-June/000242.html advisory

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-33903 updated 2025-11-21 cvss 7.5

tor: degraded congestion control through wedged RTT estimation

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.33% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

lists.torproject.org /pipermail/tor-announce/2022-June/000242.html
mailing-list, patch, vendor-advisory
security.gentoo.org /glsa/202305-11
vendor-advisory
security-tracker.debian.org /tracker/CVE-2022-33903
third-party-advisory

Sources

CVE List CVE-2022-33903
NVD CVE-2022-33903

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary