Is CVE-2026-28509 actively exploited?

No active exploitation of CVE-2026-28509 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-28509 be exploited remotely?

Yes. CVE-2026-28509 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-28509?

CVE-2026-28509 has a CVSS score of 6.3 (MEDIUM).

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MEDIUM

CVE-2026-28509

CWE-79Published: March 6, 2026· Updated: Mar 9, 2026

6.3

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:9.0th

Official Description

LangBot is a global IM bot platform designed for LLMs. Prior to version 4.8.7, LangBot’s web UI renders user-supplied raw HTML using rehypeRaw, which can lead to a cross-site scripting (XSS) vulnerability. This issue has been patched in version 4.8.7.

NVD Source

Technical Analysis

CVE-2026-28509 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 6.3.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.