CSP nonce reuse vulnerability in Discourse

published 2023-07-13 3 y ago modified 2026-09-08 2 mo ago also BIT-discourse-2023-36473 , EUVD-2023-40428 , GHSA-9f52-624j-8ppq

cvss: 6.8; 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 34%
public exploits: 0; none known

Discourse is an open source discussion platform. A CSP (Content Security Policy) nonce reuse vulnerability could allow XSS attacks to bypass CSP protection. There are no known XSS vectors at the moment, but should one be discovered, this vulnerability would allow the XSS attack to completely bypass CSP. The vulnerability is patched in the latest tests-passed, beta and stable branches.

Patch / fix

fixed in 2

bitnami discourse 3.0.5
discourse discourse 3.0.5

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-10-21)

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
OSV	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
bitnami	discourse	<3.0.5	3.0.5

Affected products

discourse discourse

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /discourse/discourse/security/advisories/GHSA-9f52-624j-8ppq
vendor-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2023-36473
web

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.

Summary