CVE-2026-50635: Limesurvey/limesurvey LimeSurvey Constructs Account Password-reset Links Vulnerability

HIGH
Advisory Identifier: GHSA-5c37-5j7w-8mh8
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CVSS 8.8
CWE-640
Published
Advisory Summary

CVE-2026-50635 is a HIGH (CVSS 8.8) limesurvey constructs account password-reset links vulnerability (CWE-640: Weak Password Recovery Mechanism for Forgotten Password) affecting Limesurvey/limesurvey libraries in the Packagist ecosystem. The issue involves limesurvey constructs account password-reset links from the client-supplied http host header without validating it.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-50635 at a Glance

CVE Identifier CVE-2026-50635
GHSA Identifier GHSA-5c37-5j7w-8mh8
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-640: Weak Password Recovery Mechanism for Forgotten Password
Affected Product Limesurvey/limesurvey
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-50635

To remediate this vulnerability, upgrade all affected Limesurvey/limesurvey dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

limesurvey/limesurvey fixed: Latest secure release 
Upgrade limesurvey/limesurvey to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for limesurvey/limesurvey

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-50635, inspect your project dependencies for Limesurvey/limesurvey:

inspect dependencies for limesurvey/limesurvey

Analyze the terminal output to locate any version of Limesurvey/limesurvey in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-640: Weak Password Recovery Mechanism for Forgotten Password, where the product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak. In Limesurvey/limesurvey, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-50635 Affected Limesurvey/limesurvey Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
limesurvey/limesurvey
 Packagist
≤ 7.0.0-beta1

References

NVD — CVE-2026-50635 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-50635
Limesurvey/limesurvey Source Repository REPOSITORY
https://github.com/LimeSurvey/LimeSurvey/pull/5032
Security Fix Commit FIX COMMIT
https://github.com/LimeSurvey/LimeSurvey/commit/ac2a4f1673de7b56e7a342c338f36e8bb077d4b3
Security Fix Commit FIX COMMIT
https://github.com/LimeSurvey/LimeSurvey/commit/b394cb64328aa6db95e3304f82c8c9e603e9ceb0
Limesurvey/limesurvey Source Repository REPOSITORY
https://github.com/LimeSurvey/LimeSurvey
www.limesurvey.org WEB
https://www.limesurvey.org
www.vulncheck.com/advisories/limesurv... WEB
https://www.vulncheck.com/advisories/limesurvey-password-reset-host-header-injection-discloses-reset-token

Frequently Asked Questions

What is CVE-2026-50635?
CVE-2026-50635 is a security vulnerability in Limesurvey/limesurvey involving LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it. under CWE-640: Weak Password Recovery Mechanism for Forgotten Password.
Which Limesurvey/limesurvey versions are affected?
Affected versions include releases prior to current release patches across affected packages: limesurvey/limesurvey.
What version fixes CVE-2026-50635?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is limesurvey/limesurvey affected?
Yes, limesurvey/limesurvey is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-50635?
CVE-2026-50635 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-50635?
CVE-2026-50635 is classified under CWE-640: Weak Password Recovery Mechanism for Forgotten Password (The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak.).
How can I check Packagist dependencies for CVE-2026-50635?
Run the dependency tree command: 'inspect dependencies for limesurvey/limesurvey'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5c37-5j7w-8mh8",
  "modified" : "2026-07-31T19:22:30Z",
  "published" : "2026-06-09T18:31:04Z",
  "aliases" : [ "CVE-2026-50635" ],
  "summary" : "LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it.",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "limesurvey/limesurvey"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "7.0.0-beta1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-50635"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/LimeSurvey/LimeSurvey/pull/5032"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/LimeSurvey/LimeSurvey/commit/ac2a4f1673de7b56e7a342c338f36e8bb077d4b3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/LimeSurvey/LimeSurvey/commit/b394cb64328aa6db95e3304f82c8c9e603e9ceb0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/LimeSurvey/LimeSurvey"
  }, {
    "type" : "WEB",
    "url" : "https://www.limesurvey.org"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/limesurvey-password-reset-host-header-injection-discloses-reset-token"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-640" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-31T19:22:30Z",
    "nvd_published_at" : "2026-06-09T18:17:10Z"
  }
}