How severe is CVE-2026-33424?

CVE-2026-33424 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2026-33424 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33424?

CVE-2026-33424 primarily affects Discourse. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-33424?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-33424 have an EU (EUVD) identifier?

Yes. CVE-2026-33424 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13904.

When was CVE-2026-33424 published?

CVE-2026-33424 was published on 2026-03-21 and last updated on 2026-06-17.

CVE-2026-33424

CVE-2026-33424 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 0% (12th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13904
Weakness: CWE-863
Affected product: Discourse
Published: 2026-03-21
Last modified: 2026-06-17

Description

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an attacker can grant access to a private message topic through invites even after they lose access to that PM. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

Frequently asked questions

What is CVE-2026-33424?: Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an attacker can grant access to a private message topic through invites even after they lose access to that PM. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
How severe is CVE-2026-33424?: CVE-2026-33424 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2026-33424 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33424?: CVE-2026-33424 primarily affects Discourse. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-33424?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33424 have an EU (EUVD) identifier?: Yes. CVE-2026-33424 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13904.
When was CVE-2026-33424 published?: CVE-2026-33424 was published on 2026-03-21 and last updated on 2026-06-17.

References

https://github.com/discourse/discourse/security/advisories/GHSA-hgcp-p7hq-cwxw

Affected products (2)

cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:*

More vulnerabilities in Discourse

CVE-2021-41163 — Critical (CVSS 10.0): Discourse is an open source platform for community discussion. In affected versions maliciously crafted requests could…
CVE-2025-53102 — Critical (CVSS 9.8): Discourse is an open-source community discussion platform. Prior to version 3.4.7 on the `stable` branch and version…
CVE-2025-48877 — Critical (CVSS 9.8): Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of…
CVE-2022-36066 — Critical (CVSS 9.1): Discourse is an open source discussion platform. In versions prior to 2.8.9 on the `stable` branch and prior to…
CVE-2022-39356 — High (CVSS 8.9): Discourse is a platform for community discussion. Users who receive an invitation link that is not scoped to a single…
CVE-2023-22468 — High (CVSS 8.8): Discourse is an open source platform for community discussion. Versions prior to 2.8.13 (stable), 3.0.0.beta16 (beta)…

All CVEs affecting Discourse →

Other CWE-863 (Incorrect Authorization) vulnerabilities

CVE-2026-48286 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9396 and earlier are affected by an Incorrect Authorization…
CVE-2026-48303 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9394 and earlier are affected by an Incorrect Authorization…
CVE-2026-44330 — Critical (CVSS 10.0): free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the…
CVE-2026-46595 — Critical (CVSS 10.0): Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of…
CVE-2026-33105 — Critical (CVSS 10.0): Improper authorization in Microsoft Azure Kubernetes Service allows an unauthorized attacker to elevate privileges over…
CVE-2026-32213 — Critical (CVSS 10.0): Improper authorization in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.

Browse all CWE-863 (Incorrect Authorization) vulnerabilities →