CVE-2026-49381Network attack vector

Browser data disclosure via stored SAML script

Published May 29, 2026 · Updated May 29, 2026

Stored XSS in JetBrains TeamCity before 2026.1 allows remote authenticated users to execute script through the SAML login page. JetBrains has not disclosed which stored SAML value reaches the page or where output encoding fails. Exploitation requires high privileges and a user to load the affected page, exposing browser-visible data without reported integrity or availability impact.

CVSS severity3.4
Low
EPSS probability0.21%
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 JetBrains TeamCity before 2026.1 allows remote authenticated users to execute script through the SAML login page. JetBrains has not disclosed which stored SAML value reaches the page or where output encoding fails. Exploitation requires high privileges and a user to load the affected page, exposing browser-visible data without reported integrity or availability impact.

The record

CVE
CVE-2026-49381
Published
May 29, 2026
Updated
May 29, 2026
Vendor
JetBrains
Product
TeamCity On-Premises
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 29, 2026CVE publishedPublication date reported by the CVE source.
  2. May 29, 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 <2026.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

JetBrains · TeamCity On-Premisesversion=0 <2026.1

Published CVSS scores

4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
3.4JetBrainsCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:N/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')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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