Piranha CMS - Stored XSS in Page Title

published 2021-10-25 5 y ago modified 2026-06-17 4 mo ago also GHSA-jvjp-vh27-r9h5 , EUVD-2021-2218

cvss: 5.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits: 0; none known

In PiranhaCMS, versions 7.0.0 to 9.1.1 are vulnerable to stored XSS due to the page title improperly sanitized. By creating a page with a specially crafted page title, a low privileged user can trigger arbitrary JavaScript execution.

Patch / fix

fixed in 1 links 1

nuget Piranha 9.2.0

github.com/PiranhaCMS/piranha.core@543bc53 commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 18 mo ago (2025-04-30)

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	3.5	AV:N/AC:M/Au:S/C:N/I:P/A:N
GitHub	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
nuget	Piranha	>=7.0.0, <9.2.0	9.2.0

Affected products

PiranhaCMS Piranha

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /PiranhaCMS/piranha.core/commit/543bc53c7dbd28c793ec960b57fb0e716c6b18d7
web, patch, third-party-advisory
whitesourcesoftware.com /vulnerability-database/CVE-2021-25977
web, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2021-25977
advisory
github.com /PiranhaCMS/piranha.core
package

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