Insufficient control of region value length in discourse-calendar

published 2024-08-30 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-19284

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

discourse-calendar is a discourse plugin which adds the ability to create a dynamic calendar in the first post of a topic. The limit on region value length is too generous. This allows a malicious actor to cause a Discourse instance to use excessive bandwidth and disk space. This issue has been patched in main the main branch. There are no workarounds for this vulnerability. Please upgrade as soon as possible.

Patch / fix

fixed in 1

discourse discourse_calendar 2024-08-28

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-08-30)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Affected products

discourse discourse-calendar

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-770 Allocation of Resources Without Limits or Throttling

References

github.com /discourse/discourse-calendar/security/advisories/GHSA-65f2-9ghp-x8h8
vendor-advisory

Sources

CVE List CVE-2024-21658
NVD CVE-2024-21658

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary