CVE-2026-52792 (GCVE-0-2026-52792)
Vulnerability from cvelistv5
Published
2026-08-19 14:49
Modified
2026-08-19 15:21
CWE
  • CWE-69 - Improper Handling of Windows ::DATA Alternate Data Stream
Summary
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.
Impacted products
Vendor Product Version
xyproto algernon Version: < 1.17.9
Create a notification for this product.
Show details on NVD website


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                "id": "CVE-2026-52792",
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                "role": "CISA Coordinator",
                "timestamp": "2026-08-19T15:20:47.938701Z",
                "version": "2.0.3"
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            "url": "https://github.com/xyproto/algernon/security/advisories/GHSA-mm6c-5j6x-hq8m"
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        "title": "CISA ADP Vulnrichment"
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          "vendor": "xyproto",
          "versions": [
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          "value": "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."
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            "vectorString": "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",
            "version": "4.0",
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      "providerMetadata": {
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        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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          "url": "https://github.com/xyproto/algernon/security/advisories/GHSA-mm6c-5j6x-hq8m"
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    "dateReserved": "2026-06-08T18:02:19.731Z",
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