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Fencer Vulns
medium 4.3

CVE-2021-32763 json

Regular Expression Denial of Service in OpenProject forum messages

published 2021-07-20 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-19531

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `<pre>` tags from the message being quoted. The `(.|\s)` part can match a space character in two ways, so an unterminated `<pre>` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2<sup>n</sup> states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.

Patch / fix

  • openproject openproject 11.3.3

Exploit prediction

0.92% chance of exploitation in the next 30 days, higher than 60% 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 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P

Affected products

  • opf openproject

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

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.