capricorn86 Happy DOM up to 20.14.5 CookieContainer CookieContainer.ts cookieMatchesURL session fixiation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.8$0-$5k0.71

Summaryinfo

A vulnerability classified as critical has been found in capricorn86 Happy DOM up to 20.14.5. This impacts the function cookieMatchesURL of the file src/cookie/CookieContainer.ts of the component CookieContainer. Performing a manipulation results in session fixiation. This vulnerability is reported as CVE-2026-118661. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in capricorn86 Happy DOM up to 20.14.5. It has been classified as critical. This affects the function cookieMatchesURL of the file src/cookie/CookieContainer.ts of the component CookieContainer. The manipulation with an unknown input leads to a session fixiation vulnerability. CWE is classifying the issue as CWE-384. Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-118661 since 10/28/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

Upgrading to version 20.14.6 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Session fixiation
CWE: CWE-384
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Happy DOM 20.14.6

Timelineinfo

10/28/2026 Advisory disclosed
10/28/2026 +0 days CVE reserved
10/28/2026 +0 days VulDB entry created
10/28/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-118661 (🔒)
GCVE (CVE): GCVE-0-2026-118661
GCVE (VulDB): GCVE-100-428217

Entryinfo

Created: 10/28/2026 21:54
Changes: 10/28/2026 21:54 (66)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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