Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). EPSS, Forum of Incident Response and Security Teams (FIRST), epss.first.org. Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-50635 is a high-severity Weak Password Recovery Mechanism for Forgotten Password (CWE-640) vulnerability in Limesurvey (inferred from references). Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Valid Accounts (T1078); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to IA-12 (Identity Proofing) and IA-5 (Authenticator Management) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-35769
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
MITRE ATT&CK v20.0
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5)
Our mappings, made for this CVE.
Identity proofing at appropriate assurance levels ensures forgotten-password recovery cannot succeed without strong verification of the user.
Authenticator management requires secure distribution, reset, and verification procedures that directly address weak password recovery flows.
Mitigating Controls (NIST CSF 2.0)
Our mappings, derived directly from the weakness types (CWEs) cited in the NVD entry via our CWE→CSF cross-walk — links open the control.
Credential lifecycle management directly includes password reset/recovery flows.
Identity proofing is the core control that prevents weak or bypassed recovery mechanisms.
Authentication policy covers strength/MFA but does not address recovery path weaknesses.
Secure SDLC reduces implementation flaws but is not specific to password-recovery design.
Mitigating Controls (ISO/IEC 27001:2022 Annex A)
Our mappings, derived directly from the weakness types (CWEs) cited in the NVD entry via our CWE→ISO cross-walk — links open the control.
A.8.29's combined programme (code review, static analysis, vulnerability scanning, penetration testing) reaches CWE-640 from both SOURCE and RUNTIME angles: pentesters routinely exercise password recovery flows for brute-force, token reuse, and information disclosure (the exact failure modes in the 2024-2025 CVE examples), and code review catches implementation flaws like missing throttling or returning the original password; the remainder is design-level weaknesses (e.g., security questions that are too common or guessable from social media) where the code looks reasonable and the weakness only surfaces under a review of the recovery design itself.
Secure-coding standards can prevent weak recovery implementations, yet the control is wider in scope.