9.8

CVE-2026-56817: netty

CVSS: 9.8v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-56817DEBIAN-CVE-2026-56817CGA-2vg5-vrgw-h8xh
Published 21-07-2026Last modified 22-07-2026
Open JSON

Vulnerability summary

CVE-2026-56817 is a critical (CVSS 9.8) vulnerability in netty. EPSS estimates a 0.69% chance of exploitation in the next 30 days, higher than 52% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.69%
0%100%
Low · +0.32 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 3
OPENSUSE-SU-2026:11394-1SUSE-SU-2026:3482-1CGA-JWRX-2PHW-JCP2

Timeline

  1. 21-07-2026
    PublishedVulnerability first disclosed.
  2. 22-07-2026
    Last modifiedVulnerability information updated.

Description

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, any caller that can deliver bytes to a Netty channel pipeline containing `XmlDecoder` can send XML with a `DOCTYPE` declaration to an `AsyncXMLInputFactory` instantiated with no security configuration, leaving DTD and entity handling active depending on Aalto XML async parser behavior and creating conditional XML external entity risk. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS metrics

9 scores · 7 sources · 2 versions

EPSS trend

Probability

0.69%

Chance of exploitation in the next 30 days

Percentile

52%

Versus all other CVEs

30-day change

+0.32 pp

From 0.37% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.69%

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

Chainguard16 products
  • apache-hop< 2.18.1-r8
  • apache-hop-fips< 2.18.1-r6
  • celeborn-0.5< 0.5.4-r30
  • celeborn-0.6< 0.6.3-r11
  • gremlin-server< 3.8.1-r2
Wolfi5 products
  • celeborn-0.6< 0.6.3-r11
  • management-api-for-apache-cassandra-5.0< 0.1.122-r2
  • tez< 0.10.5-r23
  • thingsboard-tb-mqtt-transport< 4.3.1.3-r7
  • thingsboard-tb-node< 4.3.1.3-r7
Debian1 product
  • nettyAll versions (No fix recorded)
Io.netty1 product
  • netty-codec-xml≥ 4.2.0.Final, < 4.2.16.Final | ≥ 4.1.0.Final, < 4.1.136.Final
Netty1 product
  • netty≥ 4.2.0.Final, < 4.2.16.Final | ≥ 4.1.0.Final, < 4.1.136.Final | ≥ 4.1.0, < 4.1.136 | ≥ 4.2.0, < 4.2.16
Ubuntu1 product
  • nettyAll versions (No fix recorded)

6 vendors · 25 products

References

11 links
Show all 11 references