How severe is CVE-2024-21655?

CVE-2024-21655 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2024-21655 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-21655?

CVE-2024-21655 primarily affects Discourse. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-21655?

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

Does CVE-2024-21655 have an EU (EUVD) identifier?

Yes. CVE-2024-21655 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19281.

When was CVE-2024-21655 published?

CVE-2024-21655 was published on 2024-01-12 and last updated on 2026-06-17.

CVE-2024-21655

CVE-2024-21655 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 4.3. 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-770.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-19281
Weakness: CWE-770
Affected product: Discourse
Published: 2024-01-12
Last modified: 2026-06-17

Description

Discourse is a platform for community discussion. For fields that are client editable, limits on sizes are not imposed. This allows a malicious actor to cause a Discourse instance to use excessive disk space and also often excessive bandwidth. The issue is patched 3.1.4 and 3.2.0.beta4.

Frequently asked questions

What is CVE-2024-21655?: Discourse is a platform for community discussion. For fields that are client editable, limits on sizes are not imposed. This allows a malicious actor to cause a Discourse instance to use excessive disk space and also often excessive bandwidth. The issue is patched 3.1.4 and 3.2.0.beta4.
How severe is CVE-2024-21655?: CVE-2024-21655 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2024-21655 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-21655?: CVE-2024-21655 primarily affects Discourse. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-21655?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-21655 have an EU (EUVD) identifier?: Yes. CVE-2024-21655 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19281.
When was CVE-2024-21655 published?: CVE-2024-21655 was published on 2024-01-12 and last updated on 2026-06-17.

References

https://github.com/discourse/discourse/security/advisories/GHSA-m5fc-94mm-38fx

Affected products (4)

cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*
cpe:2.3:a:discourse:discourse:3.2.0:beta1:*:*:beta:*:*:*
cpe:2.3:a:discourse:discourse:3.2.0:beta2:*:*:beta:*:*:*
cpe:2.3:a:discourse:discourse:3.2.0:beta3:*:*:beta:*:*:*

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