Paella Player: Stored XSS via caption cue text

published 2026-09-17 52 d ago modified 2026-09-24 45 d ago also EUVD-2026-82473 , GHSA-m6c8-jcw2-5r25

cvss: 8.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits: 0; none known

Paella Player is a set of libraries to create a multi stream video player. Prior to Paella Player 2.12.11 (as used in Opencast prior to 19.7 and 20.2), there is a potential XSS attack though closed captions cue text. This vulnerability is fixed in 2.12.11.

Patch / fix

fixed in 4 links 7

maven org.opencastproject:opencast-engage-paella-player-7 19.7, 20.2
npm paella-core 1.50.6
apereo opencast 19.7, 20.2
polimediaupv paella-player 2.12.11

github.com/opencast/opencast@701682c commit
github.com/polimediaupv/paella-core@94a3649 commit
github.com/polimediaupv/paella-core@9b2f14e commit
github.com/polimediaupv/paella-player@6fe4af7 commit
github.com/opencast/opencast#7736 pull request
github.com/opencast/opencast/releases/tag/19.7 release
github.com/opencast/opencast/releases/tag/20.2 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 48 d ago (2026-09-22)

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/opencast/opencast/security/advisories/GHSA-m6c8-jcw2-5r25 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
GitHub	3.1	8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
maven	org.opencastproject:opencast-engage-paella-player-7	<19.7 >=20.0, <20.2	19.7 20.2
npm	paella-core	<1.50.6	1.50.6

Affected products

opencast opencast
polimediaupv paella-player

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

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.

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

Summary