What is CVE-2026-32859?

CVE-2026-32859 is a medium-severity vulnerability in Bytedance Inc. Deerflow, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-03-27.

How severe is CVE-2026-32859?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Bytedance Inc. Deerflow

CVE-2026-32859

ByteDance DeerFlow versions prior to commit 5dbb362 contain a stored cross-site scripting vulnerability in the artifacts API that allows attackers to execute arbitrary scripts by uploading malicious HTML or script content as artifacts. Attackers can store malicious content that executes in the browser context when users view artifacts, leading to session compromise, credential theft, and arbitrary script execution.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-03-27 · last modified 2026-07-14.

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: 0.003 (24.9th percentile), scored 2026-10-10.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Bytedance Inc. Deerflow — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/bytedance/deer-flow/pull/1389 (issue-tracking)
github.com/bytedance/deer-flow/commit/5dbb3623b2f0e490c8bb3cd81b1e3b1b12eae1a6 (patch)
www.vulncheck.com/advisories/bytedance-deerflow-stored-xss-via-inline-artifact-… (third-party-advisory)

Frequently asked questions

What is CVE-2026-32859?: CVE-2026-32859 is a medium-severity vulnerability in Bytedance Inc. Deerflow, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-03-27.
How severe is CVE-2026-32859?: Medium severity. CVSS v3 base score is 5.4 out of 10.