Penpot: Stored XSS via custom font family name injected into a @font-face style rule

published 2026-08-26 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-66811

cvss: 7.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits: 0; none known

Penpot is an open-source design and prototyping platform. In versions up to and including 2.14.3, Penpot is vulnerable to stored cross-site scripting through custom font family names, which are interpolated into a @font-face CSS rule and injected into the page as HTML without sanitization. Because the backend accepts an arbitrary font-family string and the frontend writes the resulting style through innerHTML, a name containing markup such as a closing style tag followed by a script can break out of the style element and execute JavaScript on the Penpot origin. The attack is passive: any team member who opens a file referencing the malicious font triggers script execution simply by rendering the page, allowing theft of session cookies, actions performed as the victim, and access to their files and projects. This issue is fixed in version 2.15.3.

Patch / fix

fixed in 1 links 1

kaleidos penpot 2.15.3

github.com/penpot/penpot@67d9567 commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-27)

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/penpot/penpot/security/advisories/GHSA-w5hh-gj5c-5wpc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

Affected products

penpot penpot

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

CVE List CVE-2026-47666
NVD CVE-2026-47666

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary