Goobi viewer: IIIF Auth 2.0 origin parameter unsanitized — CSP malformation and reflected XSS

published 2026-10-23 16 d ago modified 2026-10-30 9 d ago also EUVD-2026-109067

cvss: 9.3; 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 17%
public exploits: 0; none known

The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. From version 25.08 to before version 26.05, the IIIF Auth 2.0 endpoints auth/login and auth/token in AuthorizationFlowResource accept an origin query parameter without validation and then (1) embed it into the Content-Security-Policy: frame-ancestors response header and (2) embed it into an HTML response body as a JavaScript single-quoted postMessage argument. Because the attacker controls both the login and token calls that initiate the flow, the unescaped value yields reflected XSS. This issue has been patched in version 26.05.

Patch / fix

links 2

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 9 d ago (2026-10-30)

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

Affected products

intranda goobi-viewer-core

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers
CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine

References

Sources

CVE List CVE-2026-55486
NVD CVE-2026-55486

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