← Vulnerability feed

Vulnerability record · CVE-2026-52792 · published 19 August 2026

CVE-2026-52792: Algernon is a small self-contained pure-Go web server.

Algernon is a small self-contained pure-Go web server. Prior to 1.17.9, Algernon on Windows selects a file handler in engine/handlers.go by calling filepath.Ext() without first rejecting NTFS-equivalent names such as x.lua::$DATA, x.lua., and x.lua . An unauthenticated client can append one of these suffixes to a public server-side script using the .lua, .tl, .po2, .amber, or .frm extension. The request path passes through URL2filename in utils/files.go, skips the renderer and execution cases, and reaches FilePage, os.Open, ReadAndLogErrors, and ToClient, while NTFS resolves the alias to the underlying script. The server consequently returns raw script source and can expose database credentials, API keys, and the SetCookieSecret value, which may permit forged session cookies. Linux and macOS hosts are not affected by this issue. This issue is fixed in version 1.17.9.

8.7 CVSS 4.0 High EPSS 0.63% · top 52.0% CWE-69 · CWE-69 Deferred
8.7CVSS 4.0 base score
0.63%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
4References
18 Sep 2026Last modified by NVD

Description

Algernon is a small self-contained pure-Go web server. Prior to 1.17.9, Algernon on Windows selects a file handler in engine/handlers.go by calling filepath.Ext() without first rejecting NTFS-equivalent names such as x.lua::$DATA, x.lua., and x.lua . An unauthenticated client can append one of these suffixes to a public server-side script using the .lua, .tl, .po2, .amber, or .frm extension. The request path passes through URL2filename in utils/files.go, skips the renderer and execution cases, and reaches FilePage, os.Open, ReadAndLogErrors, and ToClient, while NTFS resolves the alias to the underlying script. The server consequently returns raw script source and can expose database credentials, API keys, and the SetCookieSecret value, which may permit forged session cookies. Linux and macOS hosts are not affected by this issue. This issue is fixed in version 1.17.9.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/xyproto/algernon/commit/a6b0724928a0c35a29640b18ad5bd547f5e2efa6
https://github.com/xyproto/algernon/releases/tag/v1.17.9
https://github.com/xyproto/algernon/security/advisories/GHSA-mm6c-5j6x-hq8m
https://github.com/xyproto/algernon/security/advisories/GHSA-mm6c-5j6x-hq8m

Track CVE-2026-52792 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2026-58704Android Cellular Modem improper authorization allows adjacent privilege escalationAndroid's Cellular Modem component contains a logic error that bypasses permission checks, allowing an attacker within radio/adjacent range to escala…KEVEPSS 0.59%analysed4.3CVE-2026-32202Windows Shell protection mechanism failure enables network spoofingWindows Shell contains a protection mechanism failure (CWE-693) that lets an unauthorized attacker perform spoofing over a network. The flaw is rated…KEVEPSS 4.9%analysed9.8CVE-2025-40536SolarWinds Web Help Desk security control bypass allows unauthenticated accessSolarWinds Web Help Desk contains a security control bypass (CWE-693) that lets an unauthenticated attacker reach restricted functionality. It is rat…KEVEPSS 74%analysed8.8CVE-2026-21513Microsoft MSHTML security feature bypass on WindowsCVE-2026-21513 is a protection mechanism failure (CWE-693) in the Microsoft MSHTML Framework that lets an unauthorized attacker bypass a security fea…KEVEPSS 16%analysed8.8CVE-2026-21510Windows Shell protection mechanism failure allows security feature bypassWindows Shell contains a protection mechanism failure (CWE-693) that lets an unauthorized attacker bypass a security feature over a network. The flaw…KEVEPSS 24%analysed7.0CVE-2025-04117-Zip archive extraction fails to propagate Mark-of-the-Web7-Zip does not propagate the Mark-of-the-Web (MOTW) to files extracted from a crafted archive that itself carries MOTW. Because MOTW is what triggers…KEVEPSS 67%analysed7.3CVE-2024-38226Microsoft Publisher security feature bypass via local attackerCVE-2024-38226 is a security feature bypass in Microsoft Publisher, affecting Office 2019, Office Long Term Servicing Channel, and Publisher. The fla…KEVEPSS 2.7%analysed5.4CVE-2024-38217Windows Mark of the Web security feature bypassWindows Mark of the Web (MOTW) fails to properly apply its protection mechanism, allowing the reputation-based warning that normally accompanies file…KEVEPSS 10%analysed

Source: NIST National Vulnerability Database (record CVE-2026-52792), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.