CVE-2026-123318 json
In JetBrains Ktor before 3.6.1 hTTP request smuggling was possible in the CIO engine
published 3d ago modified 3d ago also EUVD-2026-118082
- cvss
- 4.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 3%
- public exploits
- 0
- none known
Summary
In JetBrains Ktor before 3.6.1 hTTP request smuggling was possible in the CIO engine
Patch / fix
- JetBrains Ktor 3.6.1
Is CVE-2026-123318 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.15% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |
Affected products
- JetBrains Ktor
Classification
- Weakness
-
- CWE-444 Inconsistent Interpretation of HTTP Requests
References
Sources
- CVE List CVE-2026-123318
- NVD CVE-2026-123318
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.