# CVE-2026-87724: tor: Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attac...

CVE-2026-87724 is fixed in tor on 1 platform, first by DEBIAN-CVE-2026-87724, released September 17, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-87724
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0043
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 9, 2026

## Description

Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state. This is TROVE-2026-032.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | tor Debian 13.5 (trixie) | 0.4.9.12-0+deb13u2 | [DEBIAN-CVE-2026-87724](https://patchblox.com/security/data/fix/linux/debian-cve-2026-87724.md) | Sep 17, 2026 |
| Linux | tor Debian 14 | 0.4.9.12-2 | [DEBIAN-CVE-2026-87724](https://patchblox.com/security/data/fix/linux/debian-cve-2026-87724.md) | Sep 17, 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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