GHSA-8vch-m3f4-q8jf

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Source
https://github.com/advisories/GHSA-8vch-m3f4-q8jf
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-8vch-m3f4-q8jf/GHSA-8vch-m3f4-q8jf.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-8vch-m3f4-q8jf
Aliases
Related
Published
2025-12-09T17:12:05Z
Modified
2026-02-04T03:09:32.992990Z
Severity
  • 7.5 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Elysia affected by arbitrary code injection through cookie config
Details

Arbitrary code execution from cookie config. If dynamic cookies are enabled (ie there exists a schema for cookies), the cookie config is injected into the compiled route without first being sanitised.

Availability of this exploit is generally low, as it requires write access to either the Elysia app's source code (in which case the vulnerability is meaningless) or write access to the cookie config (perhaps where it is assumed to be provisioned by the environment).

However when combined with GHSA-hxj9-33pp-j2cc, this vulnerability allows for a full RCE chain.

Impact

  • aot enabled (default)
  • cookie schema passed to route
  • Cookie config controllable eg. via env

Example of vulnerable code

new Elysia({
    cookie: {
        secrets: `' + console.log('pwned from secrets') + '`
    },
})
    .get("/", () => "hello world", {
        cookie: t.Cookie({
            foo: t.Any(),
        }),
    })

POC: https://github.com/sportshead/elysia-poc

Patches

Patched by 1.4.17 (https://github.com/elysiajs/elysia/pull/1564)

Reference commit: - https://github.com/elysiajs/elysia/pull/1564/commits/26935bf76ebc43b4a43d48b173fc853de43bb51e - https://github.com/elysiajs/elysia/pull/1564/commits/3af978663e437dccc6c1a2a3aff4b74e1574849e

Workarounds

Sanitize cookie-related env input

const overrideUnsafeQuote = (value: string) =>
    // '`' + value + '`'
    '`' + value.replace(/'/g, '\\`').replace(/\${/g, '$\\{') + '`'
Database specific 
{
    "github_reviewed": true,
    "nvd_published_at": "2025-12-09T20:15:54Z",
    "cwe_ids": [
        "CWE-94"
    ],
    "github_reviewed_at": "2025-12-09T17:12:05Z",
    "severity": "HIGH"
}
References

Affected packages

npm / elysia

Package

Name
elysia
View open source insights on deps.dev
Purl
pkg:npm/elysia

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.4.18

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-8vch-m3f4-q8jf/GHSA-8vch-m3f4-q8jf.json"