Summary
LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it.
LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it. The optional allowedHosts allowlist that would constrain this is undefined in the default (and documented) configuration, so LSHttpRequest::checkIsAllowedHost() results in no operation. A remote, unauthenticated attacker who submits a forgotten-password request for a known account (requiring only the target's username and email) with a spoofed Host header causes LimeSurvey to email that account a reset link whose hostname is attacker-controlled while embedding the genuine validation_key. When the recipient or an automated inbound mail-security link scanner dereferences the link, the valid reset token is disclosed to the attacker, who replays it against the legitimate host's newPassword endpoint to set a new password and take over the account.
Impact
CVE-2026-50635 has a CVSS score of 8.8 (High). 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. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
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-2026-50635? CVE-2026-50635 is a high-severity security vulnerability in limesurvey/limesurvey (composer), affecting versions <= 7.0.0-beta1. No fixed version is listed yet.
- How severe is CVE-2026-50635? CVE-2026-50635 has a CVSS score of 8.8 (High). 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 limesurvey/limesurvey are affected by CVE-2026-50635? limesurvey/limesurvey (composer) versions <= 7.0.0-beta1 is affected.
- Is there a fix for CVE-2026-50635? No fixed version is listed for CVE-2026-50635 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2026-50635 exploitable, and should I be worried? Whether CVE-2026-50635 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-2026-50635 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.