CVE-2026-5026Network attack vector

Session token theft via unsanitized SVG rendering

Published Mar 27, 2026 · Updated Mar 27, 2026

Stored XSS in Langflow OSS allows remote authenticated users to execute JavaScript in another user's browser through a malicious SVG. The image-serving endpoint returns uploaded SVG content as image/svg+xml without sanitizing embedded script. Exploitation requires an authenticated upload and victim interaction, after which the script can read authentication tokens stored in cookies.

CVSS severity7.0
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Langflow OSS allows remote authenticated users to execute JavaScript in another user's browser through a malicious SVG. The image-serving endpoint returns uploaded SVG content as image/svg+xml without sanitizing embedded script. Exploitation requires an authenticated upload and victim interaction, after which the script can read authentication tokens stored in cookies.

The record

CVE
CVE-2026-5026
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
OpenBMC Project
Product
Langflow OSS
Classifications
CWE-79, T1539
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenBMC Project · Langflow OSSversion=0

Published CVSS scores

7.0Tenable Network Security, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
5.4NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
8.3Tenable Network Security, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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