Saltcorn: Open Redirect in `POST /auth/login` due to incomplete `is_relative_url` validation (backslash bypass)_CVE-2026-42259

{
    "lastseen": "",
    "description": "Saltcorn is an extensible, open source, no-code database application builder. Prior to versions 1.4.6, 1.5.6, and 1.6.0-beta.5, Saltcorn validates the post-login dest parameter with a string check that only blocks :/ and //. Because all WHATWG-compliant browsers normalise backslashes (\\) to forward slashes (/) for special schemes, a payload such as /\\evil.com/path slips through is_relative_url(), is emitted unchanged in the HTTP Location header, and causes the browser to navigate cross-origin to an attacker-controlled domain. The bug is reachable on a default install and only requires a victim who can be tricked into logging in via a crafted Saltcorn URL. This issue has been patched in versions 1.4.6, 1.5.6, and 1.6.0-beta.5.",
    "published": "2026-05-07T18:54:57.234Z",
    "modified": "2026-05-07T18:54:57.234Z",
    "type": "cve",
    "title": "Saltcorn: Open Redirect in `POST /auth/login` due to incomplete `is_relative_url` validation (backslash bypass)",
    "source": "GitHub_M",
    "references": "https://github.com/saltcorn/saltcorn/security/advisories/GHSA-f3g8-9xv5-77gv",
    "id": "CVE-2026-42259",
    "bulletinFamily": "",
    "cwe": [
        "CWE-601"
    ],
    "cvelist": null,
    "sourceData": "saltcorn saltcorn < 1.4.6\nsaltcorn saltcorn >= 1.5.0-beta.0, < 1.5.6\nsaltcorn saltcorn >= 1.6.0-alpha.0, < 1.6.0-beta.5",
    "sourceHref": "",
    "cvss": {
        "score": 5.1,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
        "version": "4.0"
    },
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        "baseScore": 0,
        "baseSeverity": "",
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        "privilegesRequired": "",
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        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "saltcorn",
    "version": "< 1.4.6",
    "vendor": "saltcorn",
    "ai_description": "",
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    "ai_score": 0
}