Summary
tarteaucitron: data-cookie attribute can be used to delete arbitrary cookies
Full technical description
tarteaucitron provides a list of cookies and buttons to delete them. If an attacker can write HTML with data attributes, they could create an element that silently deletes a cookie when clicked and trick a user to delete this cookie.
Details
tarteaucitron.cookie.purge() is called on any element with the purgeBtn class. It does not check if the element is a legitimate tarteaucitron button or if the cookie corresponds to a service handled by tarteaucitron.
PoC
<a class="purgeBtn" data-cookie="foo">Click me!</a>
If someone has a cookie with this name and clicks on the link, the cookie is silently deleted.
Impact
The impact is limited because this only works on cookies without HttpOnly=true and the attacker has to know the name of the cookie.
CVE-2026-49977 has a CVSS score of 4.3 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.33.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-49977? CVE-2026-49977 is a medium-severity security vulnerability in tarteaucitronjs (npm), affecting versions < 1.33.0. It is fixed in 1.33.0.
- How severe is CVE-2026-49977? CVE-2026-49977 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of tarteaucitronjs are affected by CVE-2026-49977? tarteaucitronjs (npm) versions < 1.33.0 is affected.
- Is there a fix for CVE-2026-49977? Yes. CVE-2026-49977 is fixed in 1.33.0. Upgrade to this version or later.
- Is CVE-2026-49977 exploitable, and should I be worried? Whether CVE-2026-49977 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-49977 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-49977? Upgrade
tarteaucitronjsto 1.33.0 or later.