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:XSummary
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 30th 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
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V7.4.3
Mitigating Controls (NIST 800-53 r5) AI
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) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — 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) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Strong authentication-information lifecycle rules directly address weak password-recovery flows.
Secure-SDLC practices can embed strong recovery design, yet the control is broader than this single weakness.
Application-security requirements can mandate secure recovery flows, but the control covers many other requirements.
Secure-coding standards can prevent weak recovery implementations, yet the control is wider in scope.
Secure-authentication requirements include robust forgotten-password procedures.
Proper access-rights provisioning can limit who can trigger recovery, but does not fix the recovery mechanism itself.