Cyber Resilience

CVE-2026-32113

Open Redirect in Discourse 2026.1.0 – 2026.1.3

Published
31 March 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 5.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/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:X
EPSS Score 0.0019 9th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-32113 is a medium-severity Open Redirect (CWE-601) vulnerability in Discourse Discourse. Its CVSS base score is 5.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, the enter action in StaticController reads the sso_destination_url cookie and redirects to it with allow_other_host: true without validating the…

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destination URL. While this cookie is normally set during legitimate DiscourseConnect Provider flows with cryptographically validated SSO payloads, cookies are client-controlled and can be set by attackers. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Open redirect vulnerability in public-facing web app (Discourse StaticController) directly matches exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-33426Same product: Discourse Discourse
CVE-2026-46413Same product: Discourse Discourse
CVE-2026-29072Same product: Discourse Discourse
CVE-2026-27481Same product: Discourse Discourse
CVE-2026-32619Same product: Discourse Discourse
CVE-2026-45788Same product: Discourse Discourse
CVE-2026-27150Same product: Discourse Discourse
CVE-2026-27151Same product: Discourse Discourse
CVE-2026-27934Same product: Discourse Discourse
CVE-2026-32615Same product: Discourse Discourse

Affected Assets

discourse
discourse
2026.3.0 · 2026.1.0 — 2026.1.3 · 2026.2.0 — 2026.2.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-4 Information Flow Enforcement
  • SI-15 Information Output Filtering
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V3.7.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation of the sso_destination_url cookie value before it is used as a redirect target, preventing the unvalidated open redirect.

prevent

Enforces information flow policy that only permits redirects to approved internal or whitelisted hosts, blocking attacker-supplied external destinations.

prevent

Filters outbound redirect responses to ensure destination URLs conform to an approved set, mitigating the client-controlled cookie vector.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.

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.

mitigates

Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.

References