What is the CVSS score of CVE-2026-25688?

CVE-2026-25688 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Apache Answer are affected by CVE-2026-25688?

Apache Answer deployments using the AI answer feature through version 2.0.0 contain an XSS vulnerability that allows malicious scripts to execute in the browsers of any user viewing affected…. A patch is available.

How to fix or mitigate CVE-2026-25688?

Within 24 hours: identify all Apache Answer deployments with AI answer feature enabled and assess user exposure. Within 7 days: upgrade all instances to Apache Answer 2.0.1 or disable the AI answer feature pending upgrade. Within 30 days: verify upgrade completion across all environments and validate no residual malicious content in answer history.

Apache Answer CVE-2026-25688

EUVD-2026-35367 MEDIUM

Improper Neutralization of Alternate XSS Syntax (CWE-87)

2026-06-09

GHSA-hmr2-99jm-8x45

XSS Apache Answer

6.1

CVSS 3.1 · Vendor

Severity by source

Vendor (CNA) PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from Vendor (CNA) · only source for this CVE.

CVSS VectorVendor

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

CVSS changed

Jun 09, 2026 - 16:22 NVD

6.1 (MEDIUM)

Analysis Generated

Jun 09, 2026 - 08:15 vuln.today

Description PRE-NVD

Disclosed via oss-security. NVD scoring and full description are pending.

AnalysisAI

Unsanitized rendering of AI-generated response content in Apache Answer through 2.0.0 enables cross-site scripting (XSS) execution in the browsers of any user viewing affected AI-generated answers. The vulnerability (CWE-87, Improper Neutralization of Alternate XSS Syntax) arises because the AI answer rendering pipeline passes output directly to the browser DOM without stripping or encoding malicious script constructs. No public exploit code has been identified at time of analysis, and CISA KEV listing has not been confirmed, but the critical severity designation and vendor-confirmed patch at 2.0.1 indicate this is a high-priority remediation target for all deployments using the AI answer feature.

Technical ContextAI

Apache Answer is an open-source Q&A platform (answer.apache.org) used for community forums, help centers, and knowledge management. The affected component is the AI-generated answer rendering subsystem, which takes LLM-produced content and injects it into the browser view. CWE-87 (Improper Neutralization of Alternate XSS Syntax) indicates the root cause is a failure to neutralize alternate representations of XSS attack sequences - such as obfuscated or encoded script tags, event handlers, or javascript: URI patterns - that evade naive sanitization filters. This is distinct from standard reflected XSS (CWE-79): the alternate-syntax class specifically targets bypass vectors that slip through incomplete allowlists or pattern-matching defenses. Because AI-generated output can produce syntactically unusual or encoded content by nature, standard sanitization approaches are particularly susceptible to bypass in this attack surface.

RemediationAI

Upgrade to Apache Answer version 2.0.1, which is confirmed by the vendor advisory to fix this issue. The patch can be obtained from the Apache Answer project at https://answer.apache.org. If an immediate upgrade is not feasible, the most targeted compensating control is to disable the AI answer generation feature within the platform configuration, eliminating the unsanitized rendering path entirely - this has the trade-off of removing AI-assisted answers until the patch is applied. There is no available workaround that preserves AI answer functionality while mitigating the XSS risk, since the vulnerability is in the rendering layer itself. Restricting access to the Q&A platform to authenticated internal users only may reduce the audience exposed to malicious content but does not eliminate the vulnerability.