# CVE-2026-50635: LimeSurvey host header injection in password reset

Source: https://junglewise.ai/threats/cve-2026-50635-limesurvey-host-header-injection-in-password-reset  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-07-31  
License: CC BY 4.0 with a link back

CVE-2026-50635 · Severity: high · CVSS 8.8 · Published 2026-06-09

LimeSurvey, a popular open-source survey tool, is vulnerable to a flaw in its password reset process. An attacker can trick the system into sending a legitimate password reset email that contains a link pointing to a malicious server. If the user clicks this link, or if their email security software automatically scans it, the attacker can capture the secret reset token and use it to take over the user's account.

Technologies: [LimeSurvey](https://junglewise.ai/threats/technologies/limesurvey), [limesurvey/limesurvey (Packagist)](https://junglewise.ai/threats/technologies/limesurvey-limesurvey). Vendors: [LimeSurvey](https://junglewise.ai/threats/vendors/limesurvey), [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2026-50635 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50635 being exploited in the wild.

**How severe is CVE-2026-50635?** High severity, with a CVSS score of 8.8, published 9 June 2026.

**Which products and versions are affected?** LimeSurvey <= 7.0, <= 7.0.0-beta1; limesurvey/limesurvey (Packagist) <= 7.0.0-beta1, ECOSYSTEM:introduced=0,last_affected=7.0.0-beta1.

**Is there a fix for CVE-2026-50635?** A patch was published on 2026-06-09: Fix merged into master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-50635 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-50635?** Check whether you run LimeSurvey or limesurvey/limesurvey (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A Host Header Injection vulnerability exists in LimeSurvey's password reset mechanism. The application uses the client-supplied HTTP Host header to construct absolute URLs for password reset emails without proper validation, as the 'allowedHosts' allowlist is undefined by default. An unauthenticated remote attacker can trigger a password reset for a known username/email and provide a spoofed Host header. When the victim or an automated mail scanner interacts with the resulting link, the 'validation_key' is leaked to the attacker's server. The attacker can then replay this token against the legitimate 'newPassword' endpoint to gain full account access. The issue is addressed in versions following 7.0.0-beta1 by implementing a persisted allowed-hosts list.

## Affected products

- LimeSurvey LimeSurvey <= 7.0.0-beta1

## Identifiers

- CVE-2026-50635
- GHSA-5c37-5j7w-8mh8

## Timeline

- 2026-06-04: other: Fix pull request submitted
- 2026-06-09: disclosed: Initial disclosure and NVD publication
- 2026-06-09: patched: Fix merged into master branch
- 2026-07-31: advisory: GitHub Advisory reviewed and updated

## References

- [https://github.com/LimeSurvey/LimeSurvey/pull/5032](https://github.com/LimeSurvey/LimeSurvey/pull/5032)
- [https://www.limesurvey.org/](https://www.limesurvey.org/)
- [https://www.vulncheck.com/advisories/limesurvey-password-reset-host-header-injection-discloses-reset-token](https://www.vulncheck.com/advisories/limesurvey-password-reset-host-header-injection-discloses-reset-token)
- [https://github.com/LimeSurvey/LimeSurvey/commit/ac2a4f1673de7b56e7a342c338f36e8bb077d4b3](https://github.com/LimeSurvey/LimeSurvey/commit/ac2a4f1673de7b56e7a342c338f36e8bb077d4b3)
- [https://github.com/LimeSurvey/LimeSurvey/commit/b394cb64328aa6db95e3304f82c8c9e603e9ceb0](https://github.com/LimeSurvey/LimeSurvey/commit/b394cb64328aa6db95e3304f82c8c9e603e9ceb0)

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