CVE-2026-115457 json
baserCMS: Unauthenticated Stored XSS via Shortcode Expansion in Blog Comments
published 2026-10-23 17 d ago modified 2026-10-29 11 d ago also EUVD-2026-109081
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 36%
- public exploits
- 0
- none known
Summary
baserCMS is a website development framework. In versions 5.0.0 before 5.3.2 and 5.4.0 before 5.4.2, global shortcode expansion runs over the complete rendered page, including HTML-escaped blog comments supplied by unauthenticated visitors. A comment containing the BcBaser.getGoogleMaps shortcode can set apiBaseUrl to an attacker-controlled script URL, which is emitted as a script src and executes JavaScript on the site's origin when another visitor or administrator opens the article displaying that comment. Escaping raw HTML in comments does not prevent this stored cross-site scripting because shortcode processing happens after HTML rendering. Other registered shortcodes also expand in comments; Mail.getForm can embed a working contact form with a valid CSRF token. The flaw can compromise the authenticated browser context of an administrator who views the affected article. This issue has been patched in versions 5.3.2 and 5.4.2.
Patch / fix
- basercms basercms 5.3.2, 5.4.2
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 11 d ago
Exploit prediction
0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/baserproject/basercms/security/advisories/GHSA-qhv2-3j2q-v43x referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N |
Affected products
- baserproject basercms
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
Sources
- CVE List CVE-2026-115457
- NVD CVE-2026-115457
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.