Cookie injection in JetBrains Ktor client cookie storage
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
JetBrains Ktor before 3.6.1 does not validate the Domain attribute of cookies stored by its client, a weakness classified as CWE-565. A remote attacker without privileges or user interaction can inject cookies into the client. The attack is highly complex and affects integrity only to a low degree.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In JetBrains Ktor before 3.6.1 missing Domain attribute validation in client cookie storage allowed cookie injection
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade JetBrains Ktor to version 3.6.1 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Ktor (JetBrains) Fixed in 3.6.1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
JetBrains Ktor 3.6.1
3 records Highest priority Priority LOW 3 LOW
Other records, highest priority first
- TI-2026-85858 Session forgery in JetBrains Ktor via tampered encrypted session cookiesPriority LOW 37
- TI-2026-85859 HTTP request smuggling in JetBrains Ktor CIO enginePriority LOW 21
Timeline
- 2026-11-06 Threatist record created from CVE-2026-123319
- 2026-11-06 Alias added: GHSA-2qr9-2f88-gccj
References
More JetBrains vulnerabilities
- TI-2026-45031 Deserialization of untrusted data in JetBrains TeamCity KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18053 In JetBrains TeamCity before 2023.11.4 authentication bypass allowing to perform admin actions was possible KEVCVSS 3.1CRITICAL 9.8
- TI-2023-22884 In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18054 In JetBrains TeamCity before 2023.11.4 path traversal allowing to perform limited admin actions was possible KEVCVSS 3.1HIGH 7.3
- TI-2024-15905 In JetBrains TeamCity before 2023.11.3 authentication bypass leading to RCE was possible CVSS 3.1CRITICAL 9.8
- TI-2024-24589 Insufficiently protected credentials in JetBrains IntelliJ IDEA CVSS 3.1CRITICAL 9.3
Sources
- CVE-2026-123319 · CVE Program
- CVE-2026-123319 · NVD
- FIRST EPSS
- GHSA-2qr9-2f88-gccj · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences