CVE-2026-59901

Q: How do I fix CVE-2026-59901?

Upgrade netty to 4.1.136 or later.

Q: Is CVE-2026-59901 being actively exploited?

Not that we know of. CVE-2026-59901 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.26% is the estimated probability that it will be exploited in the next 30 days. That is higher than 18% of all scored CVEs.

Q: How severe is CVE-2026-59901?

CVE-2026-59901 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-59901 affect?

Published advisories record a fix for netty (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

HIGH

7.5

CVSS v3

NVD

Description

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, the `Bzip2Decoder` handler in Netty's compression codec pipeline is vulnerable to a denial-of-service attack through a malformed bzip2 stream that permanently captures the event-loop thread in an infinite loop. The vulnerability exists in the run-length encoding (RLE) state machine within [`Bzip2BlockDecompressor.read()`]. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

CWE-835

How to fix

Remediation Available

nettyNVD

Affected:< 4.1.136Fixed in:4.1.136CVE-2026-59901derived from NVD

Affected:>= 4.2.0, < 4.2.16Fixed in:4.2.16CVE-2026-59901derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.26%probability of exploitation in 30 days

18thpercentile

Low risk: more likely to be exploited than 18% of all known CVEs.

References

Vendor Advisory1

github.com

Related Vulnerabilities

Other CWE-835 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-13935	High	7.5	87%	-	Fix
CVE-2020-36227	High	7.5	78%	-	Fix
CVE-2022-0778	High	7.5	73%	-	Fix
CVE-2024-20353	High	8.6	71%	KEV	-
CVE-2023-34966	High	7.5	62%	-	Fix
CVE-2019-14241	High	7.5	61%	-	-

Common questions

How do I fix CVE-2026-59901?

Upgrade netty to 4.1.136 or later.

Is CVE-2026-59901 being actively exploited?

Not that we know of. CVE-2026-59901 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.26% is the estimated probability that it will be exploited in the next 30 days. That is higher than 18% of all scored CVEs.

How severe is CVE-2026-59901?

CVE-2026-59901 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-59901 affect?

Published advisories record a fix for netty (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-59901

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-06.