Cyber Resilience

CVE-2026-32099

Info Disclosure in Discourse 2026.1.0 – 2026.1.2

Published
19 March 2026
Modified
24 March 2026
Patch / advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0030 22th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-32099 is a medium-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Discourse Discourse. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 22th 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-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — 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. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, when a user has `hide_profile` enabled, their bio, location, and website were still exposed through the user onebox preview. An authenticated user could request a onebox for…

more

a hidden user's profile URL and receive their hidden profile fields (bio, location, website) in the response. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

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.
T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
Why these techniques?

Info disclosure vuln in public-facing web app (Discourse) directly enables T1190 exploitation and facilitates T1213 access to user profile data repo.

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

CVEs Like This One

CVE-2026-32143Same product: Discourse Discourse
CVE-2026-45780Same product: Discourse Discourse
CVE-2026-45788Same product: Discourse Discourse
CVE-2025-46813Same product: Discourse Discourse
CVE-2026-33355Same product: Discourse Discourse
CVE-2026-59828Same product: Discourse Discourse
CVE-2026-23743Same product: Discourse Discourse
CVE-2026-27481Same product: Discourse Discourse
CVE-2026-30891Same product: Discourse Discourse
CVE-2026-49256Same product: Discourse Discourse

Affected Assets

discourse
discourse
2026.3.0 · 2026.1.0 — 2026.1.2 · 2026.2.0 — 2026.2.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-4 Information Flow Enforcement
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.4.9
  • V11.7.1
  • V14.1.2
  • V14.2.4

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces the hide_profile restriction so that bio/location/website are not returned by the onebox preview endpoint.

prevent

Controls information flow from hidden user profiles to the onebox rendering path, blocking unauthorized disclosure of the restricted fields.

prevent

Limits the data visible to other authenticated users to only the minimum required when hide_profile is set, reducing the impact of the onebox exposure.

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.AA-05 mostly match
prevents

PR.AA-05 directly enforces least-privilege authorization that blocks most unauthorized disclosures, yet CWE-200 also arises from logging, error messages, and side-channel paths that access controls alone do not address.

PR.DS-10 mostly match
prevents

PR.DS-10 mostly prevents CWE-200 by directly eliminating unauthorized access to sensitive data-in-use, yet only partially addresses the weakness because CWE-200 spans many other exposure vectors outside runtime protection.

PR.IR-01 mostly match
prevents

PR.IR-01's segmentation/zero-trust controls largely eliminate network-level unauthorized access paths that enable exposure, yet CWE-200 spans many additional vectors (API responses, logs, app logic) that network controls alone cannot close.

PR.PS-06 mostly match
prevents

Secure SDLC practices catch most exposure flaws via design, testing and release controls, yet CWE-200 spans runtime/config issues a single development outcome cannot fully close.

PR.AA-01 partial match
prevents

PR.AA-01 supplies proper credential lifecycle controls that reduce unauthorized access paths, yet leaves many other exposure vectors (error messages, logging, side channels, etc.) unaddressed.

PR.AA-03 partial match
prevents

Authentication verifies actor identity and is a prerequisite for access decisions, yet addresses only one facet of the broad set of exposure vectors in CWE-200.

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.

prevents

Restricting anonymous or unknown access and encrypting high-value information limits the exposure of sensitive data that would otherwise be obtainable by unauthorized actors.

prevents

Suppressing system details, error specifics, and previous log-on information until successful authentication reduces the information an unauthenticated attacker can gather.

prevents

By requiring owners to assign sensitivity labels and corresponding handling rules, the control ensures that information is not left unmarked and therefore reduces the chance that sensitive data will be exposed to unauthorized actors.

prevents

Requiring encryption, access controls, and recipient authentication for transfers directly reduces the chance that sensitive data reaches an unauthorized observer.

prevents

Secure delivery, protected storage, and confidentiality of allocation records limit exposure of authentication material to unauthorized observers.

prevents

Requiring defined procedures, assigned roles, and technical/organizational measures for handling PII reduces the chance that sensitive personal data will be exposed to unauthorized actors through inadequate handling or missing safeguards.

References