All errata/sisyphus/ALT-PU-2026-15150-1
ALT-PU-2026-15150-1

Package update tor in branch sisyphus

Version0.4.9.9-alt1
Task#420208
Published2026-06-05
Max severityCRITICAL
Severity:

Closed issues (4)

CVE-2026-77639
MEDIUM5.3

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.

Published: 2026-08-20Modified: 2026-09-08
CVSS 3.xMEDIUM 5.3
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
CVE-2026-77640
MEDIUM5.3

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.

Published: 2026-08-20Modified: 2026-09-08
CVSS 3.xMEDIUM 5.3
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
CVE-2026-77641
HIGH8.2

tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUX_SWITCH cell fails. The return value of relay_send_command_from_edge() was ignored, so a send failure (which calls circuit_mark_for_close() and removes the leg via cfx_del_leg()) would go undetected, causing the caller to write to the now-freed current leg and resulting in a crash. This is TROVE-2026-017.

Published: 2026-08-20Modified: 2026-09-08
CVSS 3.xHIGH 8.2
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
References
CVE-2026-77642
CRITICAL9.3

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.

Published: 2026-08-20Modified: 2026-09-08
CVSS 3.xCRITICAL 9.3
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:H
References