9.1

CVE-2026-75595: netty

CVSS: 9.1v4.0CriticalAnalyzed
AliasesUBUNTU-CVE-2026-75595DEBIAN-CVE-2026-75595CGA-292j-gx7c-g4rv
Published 19-08-2026Last modified 20-08-2026
Open JSON

Vulnerability summary

CVE-2026-75595 is a critical (CVSS 9.1) vulnerability in netty. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 18.9% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.28%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:11882-1SUSE-SU-2026:4391-1

Timeline

  1. 19-08-2026
    PublishedVulnerability first disclosed.
  2. 20-08-2026
    Last modifiedVulnerability information updated.

Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause an IndexOutOfBoundsException and invoke select(ctx, null). This selects the default SslContext instead of the SNI-specific context. In deployments where per-SNI clientAuth=REQUIRE is the sole mutual TLS gate, the default SslContext uses clientAuth=NONE or clientAuth=OPTIONAL, and no application-layer certificate verification exists, an unauthenticated remote attacker can bypass the protected route's mutual TLS requirement. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.

CVSS metrics

9 scores · 7 sources · 2 versions

EPSS trend

Probability

0.28%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

-0.04 pp

From 0.32% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.28%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard145 products
  • akhq< 0.28.0-r8
  • apache-camel-karavan-devmode< 4.18.1-r12
  • apache-hop< 2.19.0-r3
  • apache-nifi-2.11< 2.11.0-r7
  • cassandra-5.0< 5.0.9-r7
Wolfi32 products
  • akhq< 0.28.0-r8
  • cassandra-5.0< 5.0.9-r7
  • cassandra-reaper< 5.0.1-r1
  • celeborn-0.6All versions (No fix recorded)
  • druid< 37.0.0-r56
Debian1 product
  • nettyAll versions (No fix recorded)
Io.netty1 product
  • netty-handler≥ 4.2.0.Final, < 4.2.17.Final | < 4.1.137.Final
Netty1 product
  • netty< 4.1.137.Final | ≥ 4.2.0.Final, < 4.2.17.Final | < 4.1.137 | ≥ 4.2.0, < 4.2.17
Ubuntu1 product
  • nettyAll versions (No fix recorded)

6 vendors · 181 products

References

14 links
Show all 14 references