CVE-2026-77640
Published: August 20th, 2026
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.
LOW
CVSS v3: 3.7
CVSS v3: 3.7
Status
| DocFilters Release | Package | State | Justification | Comment |
|---|---|---|---|---|
| 26.3 | zlib (1.3) | Needs Triage | ||
| 26.2 | zlib (1.3) | Needs Triage | ||
| 26.1 | zlib (1.3) | Needs Triage | ||
| 25.4 | zlib (1.3) | Needs Triage | ||
| 25.3 | zlib (1.3) | Needs Triage | ||
| 25.2 | zlib (1.3) | Needs Triage | ||
| 25.1 | zlib (1.3) | Needs Triage | ||
| 24.4 | zlib (1.3) | Needs Triage | ||
| 24.4.0 | zlib (1.3) | Needs Triage | ||
| 24.3 | zlib (1.3) | Needs Triage | ||
| 24.2 | zlib (1.3) | Needs Triage | ||
| 24.1 | zlib (1.3) | Needs Triage | ||
| 23.3 | zlib (1.3) | Needs Triage | ||
| 23.2 | zlib (1.2.12) | Needs Triage | ||
| 23.1 | zlib (1.2.12) | Needs Triage | ||
| 22.4 | zlib (1.2.12) | Needs Triage | ||
| 22.3 | zlib (1.2.12) | Needs Triage | ||
| 22.2 | zlib (1.2.12) | Needs Triage | ||
| 22.1 | zlib (1.2.11) | Needs Triage | ||
| 21.11 | zlib (1.2.11) | Needs Triage | ||
| 21.8 | zlib (1.2.11) | Needs Triage | ||
| 21.5.0 | zlib (1.2.11) | Needs Triage | ||
| 21.2.0 | zlib (1.2.11) | Needs Triage | ||
| 11.4.19.3667 | zlib (1.2.11) | Needs Triage | ||
| 11.4.18.3599 | zlib (1.2.11) | Needs Triage | ||
| 11.4.16.3445 | zlib (1.2.11) | Needs Triage | ||
| 11.4.15.3368 | zlib (1.2.11) | Needs Triage | ||
| 11.4.14.3263 | zlib (1.2.11) | Needs Triage | ||
| 11.4.13.3179 | zlib (1.2.11) | Needs Triage | ||
| 11.4.12.3054 | zlib (1.2.11) | Needs Triage | ||
| 11.4.11.3040 | zlib (1.2.11) | Needs Triage | ||
| 11.4.11.2990 | zlib (1.2.11) | Needs Triage | ||
| 11.4.10.2934 | zlib (1.2.11) | Needs Triage | ||
| 11.4.9.2878 | zlib (1.2.11) | Needs Triage | ||
| 11.4.8.2822 | zlib (1.2.11) | Needs Triage |
Severity score breakdown
Attack Complexity
HIGH
Attack Vector
NETWORK
Availability Impact
LOW
Base Score
3.7
Base Severity
LOW
Confidentiality Impact
NONE
Integrity Impact
NONE
Privileges Required
NONE
Scope
UNCHANGED
User Interaction
NONE
Vector String
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Version
3.1