AnythingLLM: Stored XSS Due to Unescaped Server-Side HTML Concatenation in MetaGenerator

published 2026-09-10 59 d ago modified 2026-09-10 59 d ago also EUVD-2026-75642

cvss: 5.5; 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 20%
public exploits: 0; none known

AnythingLLM is an application that turns pieces of content into context that any LLM can use as references during chatting. In 1.16.1 and earlier, the manager role can store meta_page_title or meta_page_favicon through /api/admin/system-preferences, and MetaGenerator inserts those values into production homepage HTML without escaping attribute values or text content. The values pass unchanged through server/models/systemSettings.js and reach MetaGenerator.generate() in server/index.js. #assembleMeta() in server/utils/boot/MetaGenerator.js concatenates the stored values into HTML. When an administrator visits the homepage /, injected JavaScript can read the administrator JWT and use it to create API keys, access or modify workspace and chat data, delete users, and perform other administrator actions. server/endpoints/admin.js accepts the manager-controlled settings before server/models/systemSettings.js returns them unchanged. No fixed version is available as of this review.

Patch / fix

links 1

github.com/Mintplex-Labs/anything-llm@6dff9d7 commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 59 d ago (2026-09-10)

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/Mintplex-Labs/anything-llm/security/advisories/GHSA-rh3m-xv7m-9jhf referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.5	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N

Affected products

Mintplex-Labs anything-llm

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

CVE List CVE-2026-88055
NVD CVE-2026-88055

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