Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NSummary
CVE-2026-34033 is a medium-severity Basic XSS (CWE-80) vulnerability in Apache Answer. Its CVSS base score is 5.4 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Spearphishing via Service (T1566.003); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-35371
Vulnerability Data
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) vulnerability in Apache Answer. This issue affects Apache Answer: through 2.0.0. User-supplied content was included in notification emails without proper escaping, allowing authenticated users to inject arbitrary HTML…
more
into emails sent to other users. Users are recommended to upgrade to version 2.0.1, which fixes the issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
XSS in notification emails directly enables authenticated users to deliver malicious HTML content to targets via the application's email service.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Requires validation and neutralization of untrusted input before it is placed into notification emails, directly blocking the unescaped HTML injection.
Mandates filtering/sanitization of information (user content) prior to transmission in emails, addressing the missing output escaping.
Provides integrity verification of generated email content that can detect unauthorized script insertion after the fact.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require output encoding and input validation that prevent basic XSS.
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches unneutralized script tags before release.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.
Secure SDLC mandates input validation and output encoding that directly prevent basic XSS.
Application security requirements explicitly call for neutralization of script-related HTML tags.
Secure coding standards require proper escaping of <, >, & to block XSS.