Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N N U N N L 5.3 .0038 29.4 —
AFFECTED Product Versions Fixed Tor 0.2.6.1-alpha – —
TIMELINE Aug 20 Reserved by mitre Aug 20 Published (CNA: mitre) Sep 8 RESCORED — CVE-2026-77640 (torproject Tor). CVSS 3.7 → 5.3 (NVD).
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.
| Date | Event | Detail |
|---|---|---|
| August 20, 2026 | Reserved | Reserved by mitre |
| August 20, 2026 | Published | Published (CNA: mitre) |
| September 8, 2026 | RESCORED | RESCORED — CVE-2026-77640 (torproject Tor). CVSS 3.7 → 5.3 (NVD). |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| torproject | Tor | — | 0.2.6.1-alpha | — |
Authoritative record: CVE-2026-77640 at cve.org
Vendors: torproject
Weaknesses: CWE-1284
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-77640 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
