LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it.

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · 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 · score source

EPSS

• CVE-2026-50635: 0.37% estimated exploitation activity in the next 30 days; percentile 31.22 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 validationkey. 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.

Published by the source

9 Jun 2026, 18:31 UTC

Last modified by the source

31 Jul 2026, 19:22 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5c37-5j7w-8mh8

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# Patch Next advisory brief: CVE-2026-50635

Advisory: LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it.
IDs: CVE-2026-50635, GHSA-5c37-5j7w-8mh8
Record: https://patchnext.com/advisories/cve-2026-50635 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist limesurvey/limesurvey: affected <= 7.0.0-beta1

## Suggested inspection (read-only)
- Packagist limesurvey/limesurvey: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on limesurvey/limesurvey.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5c37-5j7w-8mh8 (GitHub-reviewed advisory GHSA-5c37-5j7w-8mh8 lists affected ranges: Packagist limesurvey/limesurvey >=0 <=7.0.0-beta1)

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