# CVE-2026-77584: tor: Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams

CVE-2026-77584 is fixed in tor on 1 platform, first by DEBIAN-CVE-2026-77584, released August 21, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-77584
- Priority: High
- CVSS: 8.2 (high)
- EPSS: 0.0025
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 20, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | tor Debian 12.15 (bookworm) | 0.4.9.11-0+deb12u1 | [DEBIAN-CVE-2026-77584](https://patchblox.com/security/data/fix/linux/debian-cve-2026-77584.md) | Aug 21, 2026 |
| Linux | tor Debian 13.5 (trixie) | 0.4.9.11-0+deb13u1 | [DEBIAN-CVE-2026-77584](https://patchblox.com/security/data/fix/linux/debian-cve-2026-77584.md) | Aug 21, 2026 |
| Linux | tor Debian 14 | 0.4.9.11-1 | [DEBIAN-CVE-2026-77584](https://patchblox.com/security/data/fix/linux/debian-cve-2026-77584.md) | Aug 21, 2026 |
| Linux | tor opensuse-leap 16.0 | 0.4.9.11-bp160.1.1 | [OPENSUSE-SU-2026:21660-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21660-1.md) | Aug 25, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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