Summary
A potential Regular Expression Denial of Service (ReDoS) vulnerability was identified in tarteaucitron.js in the handling of the issuu_id parameter.
Details
The issue was caused by the use of insufficiently constrained regular expressions applied to attacker-controlled input:
if (issuu_id.match(/\d+\/\d+/)) {
issuu_embed = '#' + issuu_id;
} else if (issuu_id.match(/d=(.*)&u=(.*)/)) {
issuu_embed = '?' + issuu_id;
}
These expressions are not anchored and rely on greedy patterns (.*). When evaluated against specially crafted input, they may cause excessive backtracking, leading to high CPU consumption and potential denial of service.
Fix https://github.com/AmauriC/tarteaucitron.js/commit/f0bbdac2fdf3cd24a325fc0928c0d34abf1b7b52
The logic was simplified and hardened by removing ambiguous regular expressions and enforcing strict input validation:
if (issuu_id.match(/^\d+\/\d+$/)) {
issuu_embed = '#' + issuu_id;
} else {
issuu_embed = '?' + issuu_id;
}
This change eliminates the risk of catastrophic backtracking and prevents ReDoS conditions.
Additionally, code related to the legacy "Alexa Rank" service was removed. This service, historically provided by Alexa.com via browser toolbars and popularity rankings, has been deprecated for several years and is no longer operational. The Alexa domain is now exclusively associated with the Amazon voice assistant, and the original ranking service has been permanently discontinued.
Impact
An attacker able to control the issuu_id parameter could exploit this vulnerability to degrade performance or cause temporary service unavailability through CPU exhaustion.
No confidentiality or integrity impact was identified.
A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use. Typical impact: denial of service when input is crafted to trigger backtracking.
CVE-2026-22809 has a CVSS score of 4.4 (Medium). The vector is requires local access, high privileges required, and no user interaction. 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 (1.29.0); 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.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-22809? CVE-2026-22809 is a medium-severity inefficient regular expression (ReDoS) vulnerability in tarteaucitronjs (npm), affecting versions < 1.29.0. It is fixed in 1.29.0. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
- How severe is CVE-2026-22809? CVE-2026-22809 has a CVSS score of 4.4 (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-2026-22809? tarteaucitronjs (npm) versions < 1.29.0 is affected.
- Is there a fix for CVE-2026-22809? Yes. CVE-2026-22809 is fixed in 1.29.0. Upgrade to this version or later.
- Is CVE-2026-22809 exploitable, and should I be worried? Whether CVE-2026-22809 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-2026-22809 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-2026-22809? Upgrade
tarteaucitronjsto 1.29.0 or later.