CVE-2026-100725: http4k (Maven artifact org.http4k:http4k-core) before 6.48.0.0, 5.42.0.0, and 4.51.0.0 ships a BasicCookieStorage (client-side cookie store used by
Affects http4k-coreSource GCVE Database
Not known to be exploited · CVSS 8.3 High · fixed in 6.48.0.0 : patch http4k-core soon.
Data as of 10 Nov 2026, 23:24 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.3 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 6.5 |
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.48.0.0, 5.42.0.0, 4.51.0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade org.http4k/http4k-core to 6.48.0.0, 5.42.0.0 or 4.51.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Mavenorg.http4k/http4k-corepkg:maven/org.http4k/http4k-coreOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, avoid sharing a single BasicCookieStorage instance across multiple origins or schemes. Use separate cookie storage instances per origin to prevent cookie leakage and ensure Secure cookies are only sent over HTTPS.
Description
http4k-core versions before 6.48.0.0, 5.42.0.0, and 4.51.0.0 include a BasicCookieStorage implementation that does not properly enforce RFC 6265 cookie scoping rules. This flaw allows cookies intended for one origin or scheme to be sent to others, and Secure cookies may be transmitted over unencrypted HTTP connections. Clients using BasicCookieStorage for multiple origins or schemes are affected, while those using it for a single origin are not.
References
- github.com/http4k/http4k/security/advisories/GHSA-pr33-38xx-6r26 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-100725 (opens in a new tab)
- github.com/http4k/http4k/commit/6a9b44d743 (opens in a new tab)
- vulncheck.com/advisories/http4k-before-6.48.0.0-cookie-scoping-bypass-via-basiccookiestorage (opens in a new tab)