Vulnerability details
CVE-2026-62243
netty netty
Netty 4.2.0 through 4.2.16 TLS Hostname Verification Bypass
CVSS 4.0
8.7High
Official description
Netty (io.netty:netty-handler) versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain (non-extended) X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable (Java 25+). In this configuration the OpenSSL client does not perform hostname verification, allowing a man-in-the-middle attacker to present a certificate issued for a different hostname that is accepted without validation. Fixed in 4.2.17.Final and 4.1.137.Final.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.7High | 4.0 | CVEProject cvelistV5 (CNA) (VulnCheck) | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| 7.5High | 3.1 | CVEProject cvelistV5 (CNA) (VulnCheck) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| netty | netty | v < 4.1.137.Final | CVEProject cvelistV5 (CNA) |
| netty | netty | 4.2.0.Final ≤ v < 4.2.16.Final | CVEProject cvelistV5 (CNA) |
References and advisories
2
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Details
- Published
- 2026-08-22
- Last updated
- 2026-08-24
- State
- Published
- Assigner (CNA)
- VulnCheck
Exploit prediction (EPSS)
0.15%
Probability of exploitation in 30 days
4.6%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-297Improper Validation of Certificate with Host Mismatch