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.

CVE-2026-77584

CVE-2026-77584HIGH

torproject Tor — Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams.

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  H  L    8.2   .0025   14.8     —

AFFECTED
  Product  Versions         Fixed
  Tor      0.4.8.1-alpha –  —

TIMELINE
  Aug 20  Reserved by mitre
  Aug 20  Published (CNA: mitre)
  Sep 16  RESCORED — CVE-2026-77584 (torproject Tor). CVSS 7 → 8.2 (NVD).

CWE-821 · CNA: mitre · CVSS v3.1 · 1 reference · NVD status: Analyzed

Description

Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the same circuit, attaching an exit stream that would later end up orphan leaving a dangling circuit back-pointer and a use-after-free (UAF) when the circuit is freed. This is TROVE-2026-025.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
August 20, 2026	Reserved	Reserved by mitre
August 20, 2026	Published	Published (CNA: mitre)
September 16, 2026	RESCORED	RESCORED — CVE-2026-77584 (torproject Tor). CVSS 7 → 8.2 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
torproject	Tor	—	0.4.8.1-alpha	—

Weaknesses

CWE-821

References (1)

https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.10/ChangeLog [Release Notes, Vendor Advisory]

Authoritative record: CVE-2026-77584 at cve.org

Vendors: torproject

Weaknesses: CWE-821

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-77584 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.