How severe is CVE-2026-27151?

CVE-2026-27151 has a CVSS 3.x base score of 2.7, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-27151 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27151?

CVE-2026-27151 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-2026-27151?

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

Does CVE-2026-27151 have an EU (EUVD) identifier?

Yes. CVE-2026-27151 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8890.

When was CVE-2026-27151 published?

CVE-2026-27151 was published on 2026-02-26 and last updated on 2026-06-17.

CVE-2026-27151

CVE-2026-27151 is a low-severity vulnerability in Discourse with a CVSS 3.x base score of 2.7. 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-862.

Key facts

Severity: Low (CVSS 3.x base score 2.7)
CVSS v4: 1.3
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8890
Weakness: CWE-862
Affected product: Discourse
Published: 2026-02-26
Last modified: 2026-06-17

Description

Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, the `move_posts` action only checked `can_move_posts?` on the source topic but never validated write permissions on the destination topic. This allowed TL4 users and category group moderators to move posts into topics in categories where they lack posting privileges (e.g., read-only categories or categories with group-restricted write access). Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.

Frequently asked questions

What is CVE-2026-27151?: Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, the `move_posts` action only checked `can_move_posts?` on the source topic but never validated write permissions on the destination topic. This allowed TL4 users and category group moderators to move posts into topics in categories where they lack posting privileges (e.g., read-only categories or categories with group-restricted write access). Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
How severe is CVE-2026-27151?: CVE-2026-27151 has a CVSS 3.x base score of 2.7, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-27151 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27151?: CVE-2026-27151 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-2026-27151?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-27151 have an EU (EUVD) identifier?: Yes. CVE-2026-27151 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8890.
When was CVE-2026-27151 published?: CVE-2026-27151 was published on 2026-02-26 and last updated on 2026-06-17.

References

https://github.com/discourse/discourse/security/advisories/GHSA-m69h-9m2g-cfgw

Affected products (2)

cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2026.2.0:*:*:*:latest:*:*:*

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