CVE-2026-73564
frp is a fast reverse proxy. From 0.53.0 until 0.70.1, frp's optional SSH Tunnel Gateway in pkg/ssh/server.go parses an SSH exec channel request by adding 4 to an attacker-controlled four-byte big-endian length. A length of 0xFFFFFFFF makes the uint32 addition wrap to 3, defeats the payload bounds check, and causes payload[4:3] to panic in TunnelServer.handleNewChannel. When no authorized-keys file is configured, sshConfig.NoClientAuth permits an unauthenticated peer to reach this channel phase before the frp token is checked, so a single five-byte request terminates the frps process and drops every active tunnel. This issue is fixed in version 0.70.1.
- CVSS 4.0
- 8.7
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-129, CWE-190
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-26gq-p25f-99cp | Go | github.com/fatedier/frp | >=0.53.0 <0.70.1 | 0.70.1 |
| GO-2026-6103 | Go | github.com/fatedier/frp | >=0.53.0 <0.70.1 | 0.70.1 |
References
- https://github.com/fatedier/frp/commit/7dc7be930e2452ae93fd32f2a77f8c6fcd0b652b
- https://github.com/fatedier/frp/pull/5428
- https://github.com/fatedier/frp/releases/tag/v0.70.1
- https://github.com/fatedier/frp/security/advisories/GHSA-26gq-p25f-99cp
- https://github.com/fatedier/frp/security/advisories/GHSA-26gq-p25f-99cp