Algernon is a small self-contained pure-Go web server. Prior to 1.17.6, in engine/luahandler.go, the sync.RWMutex protecting LoadCommonFunctions is released before L.Push() and L.PCall() execute. Since gopher-lua's LState is explicitly not goroutine-safe, concurrent requests race on the shared state causing Lua VM corruption. The Go race detector confirms this immediately under modest concurrency (ab -n 1000 -c 100). This vulnerability is fixed in 1.17.6.
History

Tue, 26 May 2026 17:00:00 +0000

Type Values Removed Values Added
Description Algernon is a small self-contained pure-Go web server. Prior to 1.17.6, in engine/luahandler.go, the sync.RWMutex protecting LoadCommonFunctions is released before L.Push() and L.PCall() execute. Since gopher-lua's LState is explicitly not goroutine-safe, concurrent requests race on the shared state causing Lua VM corruption. The Go race detector confirms this immediately under modest concurrency (ab -n 1000 -c 100). This vulnerability is fixed in 1.17.6.
Title Algernon: Race Condition in handle() shared LState
Weaknesses CWE-362
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-26T16:31:55.696Z

Reserved: 2026-05-04T20:24:31.916Z

Link: CVE-2026-43981

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-26T17:16:45.950

Modified: 2026-05-26T17:16:45.950

Link: CVE-2026-43981

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.