Backend session compromise via unencoded stored user names
Published Apr 1, 2026 · Updated Apr 1, 2026
Stored XSS in CI4MS before 0.31.0.0 allows remote authenticated users to execute JavaScript in backend users' browsers. The /backend/users creation flow stores the name and surname fields without validation, then inserts them into the users listing HTML without output encoding. Low-privileged access to create a user is required; the payload runs when an authenticated backend user loads the listing, exposing that user's session and authorized actions.
Summary
What happened
Stored XSS in CI4MS before 0.31.0.0 allows remote authenticated users to execute JavaScript in backend users' browsers. The /backend/users creation flow stores the name and surname fields without validation, then inserts them into the users listing HTML without output encoding. Low-privileged access to create a user is required; the payload runs when an authenticated backend user loads the listing, exposing that user's session and authorized actions.
The record
- CVE
- CVE-2026-34571
- Published
- Apr 1, 2026
- Updated
- Apr 1, 2026
- Vendor
- Ci4MS
- Product
- CI4MS
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 1, 2026CVE publishedPublication date reported by the CVE source.
- Apr 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.31.0.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GitHub advisory stored-XSS reproductionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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