CVE-2026-4420 — Stored XSS via Page Creating functionality in Bludit
Bludit is vulnerable to Stored Cross-Site Scripting (XSS) in its page creating functionality. An authenticated attacker with page creation privileges (such as Author, Editor, or Administrator) can embed a malicious JavaScript payload in the tags field of a newly created article. This payload will be executed when a victim visits the URL of the uploaded resource. The uploaded resource itself is accessible without authentication. Critically, this vulnerability could be used to automatically create a new site administrator if the victim has enough privileges. The vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only versions 3.17.2 and 3.18.0 were tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+3
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Bludit Bludit).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.1 | CVSS 4.0 | Medium | — | — | cvd@cert.pl via NIST National Vulnerability Database |
| 5.1 | CVSS 4.0 | Medium | — | — | CERT-PL via CVE Program (cve.org) e CISA ADP |
| 5.4 | CVSS 3.1 | Medium | 2.3 | 2.7 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.27%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor CSP violation reports and script payloads in reflected parameters.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · bludit/bludit
- SSVC assessment updated
- Record published
- CVSS changed · 5.4
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-72576 Bludit - Stored Cross-Site Scripting via Malicious SVG Logo Upload Aug 10, 2026
- High CVE-2026-46657 Bludit's persistent authentication tokens not revoked upon account disablement Jun 8, 2026
- High CVE-2026-46656 Bludit CMS has improper authorization and mediation failure leading to persistent ghost sessions Jun 8, 2026
- Medium CVE-2026-41456 Bludit CMS Reflected XSS via Search Plugin Apr 21, 2026
- Medium CVE-2026-25100 Stored XSS via SVG File Upload in Bludit Mar 27, 2026
- Critical CVE-2026-25101 Session Fixation in Bludit Mar 27, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-4420 is "Stored XSS via Page Creating functionality in Bludit", rated Medium. It affects Bludit (Bludit); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. EPSS 0.27% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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