CVE-2023-3550Stored XSS leads to privilege escalation in MediaWiki v1.40.0
- 7.3HighCVSS base score
- 1.4%Exploitation in 30 daysEPSS · top 27% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
Mediawiki v1.40.0 does not validate namespaces used in XML files. Therefore, if the instance administrator allows XML file uploads, a remote attacker with a low-privileged user account can use this exploit to become an administrator by sending a malicious link to the instance administrator.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By Fluid Attacks
- 3 months later
· 3 months later
Published
- 17 months later
· 17 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| Fluid AttacksCNA (assigner) | 3.1 | High7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |
| NVDNVD · Modified | 3.1 | High7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 1.4% · top 27% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.3.
Affected products
References
References5
- https://fluidattacks.com/advisories/blondie/ (opens in a new tab)x_transferred
- https://www.mediawiki.org/wiki/MediaWiki/ (opens in a new tab)x_transferred
- https://www.debian.org/security/2023/dsa-5520 (opens in a new tab)x_transferred
- https://lists.debian.org/debian-lts-announce/2023/11/msg00027.html (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/FU2FGUXXK6TMV6R52VRECLC6XCSQQISY/ (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2023-44206 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2023-3550)Record last updated .