{"id":"CVE-2026-73564","summary":"frp: Unauthenticated Remote Denial of Service in the frp SSH Tunnel Gateway via Integer Overflow","details":"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.","aliases":["GHSA-26gq-p25f-99cp","GO-2026-6103"],"modified":"2026-09-09T18:26:44.896473446Z","published":"2026-08-13T17:35:46.762Z","related":["openSUSE-SU-2026:21761-1"],"database_specific":{"cwe_ids":["CWE-129","CWE-190"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73564.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/fatedier/frp/releases/tag/v0.70.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73564.json"},{"type":"ADVISORY","url":"https://github.com/fatedier/frp/security/advisories/GHSA-26gq-p25f-99cp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73564"},{"type":"FIX","url":"https://github.com/fatedier/frp/commit/7dc7be930e2452ae93fd32f2a77f8c6fcd0b652b"},{"type":"FIX","url":"https://github.com/fatedier/frp/pull/5428"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fatedier/frp","events":[{"introduced":"051299ec25638895e36779c305abf554671b4f68"},{"fixed":"7dc7be930e2452ae93fd32f2a77f8c6fcd0b652b"},{"fixed":"fa3bcca2b0c4753cd4f0e2ab189dd6a5a6a15708"}],"database_specific":{"extracted_events":[{"introduced":"0.53.0"},{"fixed":"0.70.1"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v0.70.0","v0.69.1","v0.69.0","v0.68.1","v0.68.0","v0.67.0","v0.66.0","v0.65.0","v0.64.0","v0.63.0","v0.62.1","v0.62.0","v0.61.2","v0.61.1","v0.61.0","v0.60.0","v0.59.0","v0.58.1","v0.58.0","v0.57.0","v0.56.0","v0.55.1","v0.55.0","v0.54.0","v0.53.2","v0.53.1","v0.53.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73564.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}