CVE-2026-77639
Fixed in a distro release EPSS <1%CVSS 5.3
Tor before 0.4.9.9 was prone to a compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022.
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 |