This page tracks the Debian fix status. The vulnerability itself is described on the main CVE page.
View CVE-2026-77640 →
DEBIAN-CVE-2026-77640
tor before 0.4.9.9 was prone to an infinite loop when decompressing a truncated zlib/gzip stream with done=1. A truncated stream never reaches Z_STRE...
Original description
The description as published by the source.
tor before 0.4.9.9 was prone to an infinite loop when decompressing a truncated zlib/gzip stream with done=1. A truncated stream never reaches Z_STREAM_END, causing zlib to return Z_BUF_ERROR with no input remaining, which buf_add_compress() mistook for a full output buffer and retried forever. Fixed by returning TOR_COMPRESS_ERROR in that case so the caller can abort cleanly. This is TROVE-2026-021.
Source: OSV.dev (Open Source Vulnerabilities) OSV
Affected packages
Debian:12
tor
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.9.9-1"}]}]
Debian:13
tor
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.9.11-0+deb13u1"}]}]
Debian:14
tor
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.9.9-1"}]}]
References
- advisory security-tracker.debian.org