CVE-2026-77640

Published Aug 20, 2026

Last updated 3 days ago

Overview

Description
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
cve@mitre.org
NVD status
Received

Risk scores

CVSS 3.1

Type
Secondary
Base score
3.7
Impact score
1.4
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Severity
LOW

Weaknesses

cve@mitre.org
CWE-1284

Social media

Hype score
Not currently trending

References

Sources include official advisories and independent security research.