How severe is CVE-2026-33355?

CVE-2026-33355 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-2026-33355 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33355?

CVE-2026-33355 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-2026-33355?

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

Does CVE-2026-33355 have an EU (EUVD) identifier?

Yes. CVE-2026-33355 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13337.

When was CVE-2026-33355 published?

CVE-2026-33355 was published on 2026-03-19 and last updated on 2026-06-17.

CVE-2026-33355

CVE-2026-33355 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13337
Weakness: CWE-200
Affected product: Discourse
Published: 2026-03-19
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, the `/private-posts` endpoint did not apply post-type visibility filtering, allowing regular PM participants to see whisper posts in PM topics they had access to. 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-2026-33355?: Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the `/private-posts` endpoint did not apply post-type visibility filtering, allowing regular PM participants to see whisper posts in PM topics they had access to. 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-2026-33355?: CVE-2026-33355 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-2026-33355 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33355?: CVE-2026-33355 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-2026-33355?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33355 have an EU (EUVD) identifier?: Yes. CVE-2026-33355 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13337.
When was CVE-2026-33355 published?: CVE-2026-33355 was published on 2026-03-19 and last updated on 2026-06-17.

References

Affected products (2)

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

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