How severe is CVE-2026-33428?

CVE-2026-33428 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-33428 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33428?

CVE-2026-33428 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-2026-33428?

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

Does CVE-2026-33428 have an EU (EUVD) identifier?

Yes. CVE-2026-33428 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13912.

When was CVE-2026-33428 published?

CVE-2026-33428 was published on 2026-03-21 and last updated on 2026-06-17.

CVE-2026-33428

CVE-2026-33428 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 6.5. 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 6.5)
CVSS v4: 4.9
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13912
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, a non-staff user with elevated group membership could access deleted posts belonging to any user due to an overly broad authorization check on the deleted posts index endpoint. 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-2026-33428?: Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, a non-staff user with elevated group membership could access deleted posts belonging to any user due to an overly broad authorization check on the deleted posts index endpoint. 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-2026-33428?: CVE-2026-33428 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-33428 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33428?: CVE-2026-33428 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-2026-33428?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33428 have an EU (EUVD) identifier?: Yes. CVE-2026-33428 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13912.
When was CVE-2026-33428 published?: CVE-2026-33428 was published on 2026-03-21 and last updated on 2026-06-17.

References

https://github.com/discourse/discourse/security/advisories/GHSA-frcw-p4mc-x6mp

Affected products (2)

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

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