Session fixation via unchecked cookie domains
Published Sep 15, 2026 · Updated Sep 15, 2026
Cookie validation failure in http4s before 0.23.35 and 1.0.0-M1 through 1.0.0-M46 allows remote attackers to fix sessions via crafted responses. CookieJar stores a response cookie's Domain attribute verbatim without checking that it domain-matches the response host or rejecting public suffixes. Exploitation requires one jar to contact both an attacker-controlled or compromised server and a trusted host, enabling security-sensitive cookie replacement.
Summary
What happened
Cookie validation failure in http4s before 0.23.35 and 1.0.0-M1 through 1.0.0-M46 allows remote attackers to fix sessions via crafted responses. CookieJar stores a response cookie's Domain attribute verbatim without checking that it domain-matches the response host or rejecting public suffixes. Exploitation requires one jar to contact both an attacker-controlled or compromised server and a trusted host, enabling security-sensitive cookie replacement.
The record
- CVE
- CVE-2026-69214
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- http4s
- Product
- http4s
- Classifications
- CWE-565, CWE-384, T1550.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.23.35
- Affected versionversion=>= 1.0.0-M1, < 1.0.0-M47
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo