CVE-2026-77640
Fixed in a distro release EPSS <1%CVSS 3.7
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.
Products: torproject tor
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | tor | 0.4.9.9-1 |
| Debian 13 | tor | 0.4.9.11-0+deb13u1 |
| Debian 14 | tor | 0.4.9.9-1 |
| Ubuntu 22.04 LTS | tor | no fix |
| Ubuntu 24.04 LTS | tor | no fix |
| Ubuntu 26.04 LTS | tor | no fix |
| Ubuntu Pro 14.04 LTS | tor | no fix |
| Ubuntu Pro 16.04 LTS | tor | no fix |
| Ubuntu Pro 18.04 LTS | tor | no fix |
| Ubuntu Pro 20.04 LTS | tor | no fix |