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

No CVSS.

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-13 18:18

Updated : 2026-08-13 18:18

NVD link : CVE-2026-73564

Mitre link : CVE-2026-73564

CVE.ORG link : CVE-2026-73564

JSON object : View

Products Affected

No product.

CWE

CWE-129

Improper Validation of Array Index

CWE-190

Integer Overflow or Wraparound

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