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CVE-2026-118661

medium

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface.

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Prior to 20.14.6, Happy DOM's CookieContainer in src/cookie/CookieContainer.ts does not correctly validate or match Domain cookie attributes. It can accept a Domain unrelated to the origin setting the cookie, including a public suffix, and separately treats an unrelated suffix-sharing hostname as a match because cookieMatchesURL does not enforce a DNS-label boundary. In server-side rendering and prerendering applications that contact attacker-controlled origins and then make requests to a victim origin, these behaviors can plant and deliver a forged cookie, enabling cookie injection or session fixation. This issue is fixed in version 20.14.6.

CVSS
6.5
6.5 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity source: NVD CVSS v3.1 (security-advisories@github.com)
Timeline (UTC)
Published: 2026-10-28 21:16
Modified: 2026-10-28 21:16
NVD status: Received
Last synced 12 hours ago
Verified against the source API 2026-10-28 22:10 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

Not reported by the source (unknown — not "none").

Weakness classification (CWE)

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-28 22:10 UTC · record ↗

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