Security incident · CVE-2026-118661
Happy DOM has cookie scope forgery: no DNS-label boundary on Domain= matching , attacker origin sets victim cookies
Published Oct 28, 2026 · Happy DOM has cookie
Last checked Nov 4, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-118661. EPSS is 0.27%. Act only if a listed version of Happy DOM has cookie is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Happy DOM has cookie).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.27%
- Remediation
- Not established
- Affected products
- npm happy-dom · package npm
A cookie-scoping bug in happy-dom lets an attacker origin set cookies that a victim origin then receives, diverging from browser semantics.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- npm happy-domversion unspecified
- package npmversion unspecified
How to fix CVE-2026-118661
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-118661. EPSS is 0.27%. Act only if a listed version of Happy DOM has cookie is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.27%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 28, 2026 · GitLab Advisory Database
Detected
A cookie-scoping bug in happy-dom lets an attacker origin set cookies that a victim origin then receives, diverging from browser semantics.
Sources
- CVE.orgVulnerability recordCVE-2026-118661
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-118661
30-day exploitation probability 0.27%
first.org - GitLab Advisory DatabasePackage advisoryCVE-2026-118661
A cookie-scoping bug in happy-dom lets an attacker origin set cookies that a victim origin then receives, diverging from browser semantics.
advisories.gitlab.com - Snyk Vulnerability DatabasePackage advisorySNYK-JS-HAPPYDOM-21826828
Reliance on Cookies without Validation and Integrity Checking
security.snyk.io
Freshness
Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSNov 4, 2026
- Snyk Vulnerability DatabaseNov 1, 2026
- GitLab Advisory DatabaseOct 30, 2026
- CVE.orgOct 29, 2026