XSS in N/a

CVE-2026-51153

Stored Cross-Site Scripting (XSS) in TaskRunHandler.post() in web/handlers/task.py in QD 20220208 through 20250803. When a task is run via /task/<taskid>/run, the handler renders task log content (logtmp) into the HTML response using Python % string formatting without HTML encoding. logtmp is populated from the exception object or from new_env.variables.__log__, which is attacker-controlled via the template extract_variables mechanism. A low-privileged authenticated attacker can create a crafted HAR template that extracts arbitrary HTML/JavaScript into the __log__ variable via the api://util/unicode endpoint. When a victim triggers the task run, the embedded script executes in the victim browser within the QD application context.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (13.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-51153: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-51153?
CVE-2026-51153 is a medium-severity vulnerability in N/a, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-08-31.
How severe is CVE-2026-51153?
Medium severity. CVSS v3 base score is 5.4 out of 10.