How severe is CVE-2026-34947?

CVE-2026-34947 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-34947 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34947?

CVE-2026-34947 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-2026-34947?

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

Does CVE-2026-34947 have an EU (EUVD) identifier?

Yes. CVE-2026-34947 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18882.

When was CVE-2026-34947 published?

CVE-2026-34947 was published on 2026-04-03 and last updated on 2026-06-17.

CVE-2026-34947

CVE-2026-34947 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 5.3. 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 5.3)
CVSS v4: 2.7
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18882
Weakness: CWE-200
Affected product: Discourse
Published: 2026-04-03
Last modified: 2026-06-17

Description

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, staged user custom fields and username are exposed on public invite pages without email verification. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

Frequently asked questions

What is CVE-2026-34947?: Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, staged user custom fields and username are exposed on public invite pages without email verification. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.
How severe is CVE-2026-34947?: CVE-2026-34947 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-34947 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34947?: CVE-2026-34947 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-2026-34947?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34947 have an EU (EUVD) identifier?: Yes. CVE-2026-34947 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18882.
When was CVE-2026-34947 published?: CVE-2026-34947 was published on 2026-04-03 and last updated on 2026-06-17.

References

https://github.com/discourse/discourse/security/advisories/GHSA-4rcw-wq9x-54qw

Affected products (2)

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

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