CVE-2026-77642 json
tor before 0.4.9.9 was prone to an out-of-bounds write when parsing a consensus or detached signature with unexpected signature digest type.
published 2026-08-20 2 mo ago modified 2026-10-18 21 d ago also EUVD-2026-63665
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 29%
- public exploits
- 0
- none known
Summary
tor before 0.4.9.9 was prone to an out-of-bounds write when parsing a consensus or detached signature with unexpected signature digest type. Impact is minor for most Tor roles, but potentially major for directory authorities. This is TROVE-2026-019.
Patch / fix
- torproject Tor 0.4.9.9
- tor Debian 14, Debian 12 0.4.9.9-1
- tor Debian 13 0.4.9.11-0+deb13u1
debian advisories DEBIAN-CVE-2026-77642
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-2026-77642 updated cvss 7.5
tor: Tor: Denial of Service via out-of-bounds write in signature parsing
-
Red Hat All currently supported Red Hat productsnot 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
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.35% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:H |
| NVD | 3.1 | 9.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:H |
Affected products
- torproject Tor
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
gitlab.torproject.org
/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog
permissions-required, release-notes, vendor-advisory
Sources
- CVE List CVE-2026-77642
- NVD CVE-2026-77642
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.