Cyber Resilience

CVE-2026-35399

HighPublic PoC

Published: 06 April 2026

Published
06 April 2026
Modified
09 April 2026
KEV Added
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Patch
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CVSS Score v4 8.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0029 20.3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-35399 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Wegia Wegia. Its CVSS base score is 8.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 20.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

WeGIA is a Web manager for charitable institutions. Prior to 3.6.9, a stored XSS vulnerability allows an attacker to inject malicious scripts through a backup filename. This could lead to unauthorized execution of malicious code in the victim's browser, compromising…

more

session data or executing actions on behalf of the user. This vulnerability is fixed in 3.6.9.

CWE(s)
CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
attack.mitre.org →
Why these techniques?

Stored XSS via backup filename directly enables browser session hijacking by executing attacker-controlled scripts that steal session data or perform actions as the victim.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

wegia
wegia
≤ 3.6.9

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

SI-10 Information Input Validation
addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

SI-15 Information Output Filtering
addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References