CVE-2026-69215Network attack vectorHinoki check available

Cookie disclosure via substring domain and path matching

Published Sep 15, 2026 · Updated Sep 15, 2026

Cookie disclosure in http4s CookieJar before 0.23.35 and before 1.0.0-M47 allows remote attackers to steal cookies via crafted hosts. The middleware uses unanchored substring tests for cookie Domain and Path values instead of RFC 6265 boundary and prefix rules, so example.com cookies match evilexample.com. Exploitation requires an application to reuse the same jar and make an attacker-influenced outbound request, exposing session or authentication cookies and enabling outbound-session hijacking.

CVSS severityUnavailable
Unscored
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Cookie disclosure in http4s CookieJar before 0.23.35 and before 1.0.0-M47 allows remote attackers to steal cookies via crafted hosts. The middleware uses unanchored substring tests for cookie Domain and Path values instead of RFC 6265 boundary and prefix rules, so example.com cookies match evilexample.com. Exploitation requires an application to reuse the same jar and make an attacker-influenced outbound request, exposing session or authentication cookies and enabling outbound-session hijacking.

The record

CVE
CVE-2026-69215
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
http4s
Product
http4s
Classifications
T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=< 0.23.35
  2. Affected versionversion=>= 1.0.0-M1, < 1.0.0-M47

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

http4s · http4sversion=< 0.23.35; version=>= 1.0.0-M1, < 1.0.0-M47

Published CVSS scores

No CVSS assessment is available in this record.

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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