PT-2026-43297 · Xyproto · Algernon

Published 2026-05-26 · Updated 2026-05-26 · CVE-2026-43981

Mitre

CVSS v4.0

8.2

High

Base vector

AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Fix

Race Condition

Weakness Enumeration

CWE-362

Related Identifiers

CVE-2026-43981

Affected Products

Algernon

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-43981 · Security Note
• https://github.com/xyproto/algernon/security/advisories/GHSA-rr2f-4wrm-h6rg · Note
• https://github.com/xyproto/algernon/issues/172 · Note