CVE-2026-41635: Apache MINA's AbstractIoBuffer.resolveClass() contains two branches, one of them (for static classes or primit

Q: How do I fix CVE-2026-41635?

mina: upgrade to 2.0.28, 2.1.11, 2.2.6. Exact commands for each OS are on this page.

Q: Is CVE-2026-41635 being exploited?

CVE-2026-41635 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-41635 affect?

CVE-2026-41635 affects mina. Severity is critical (CVSS 9.8). Apache MINA's AbstractIoBuffer.resolveClass() contains two branches, one of them (for static classes or primitive types) does not check the class at all, bypassing the classname allowlist and allowing arbitrary code to be executed. The

Q: How urgent is CVE-2026-41635?

Priority 60/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-41635 is a critical-severity flaw (CVSS 9.8) affecting mina. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Apache MINA's AbstractIoBuffer.resolveClass() contains two branches, one of them (for static classes or primitive types) does not check the class at all, bypassing the classname allowlist and allowing arbitrary code to be executed. The fix checks if the class is present in the accepted class filter before calling Class.forName(). Affected versions are Apache MINA 2.0.0 <= 2.0.27, 2.1.0 <= 2.1.10, and 2.2.0 <= 2.2.5. The problem

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-04-27
Last modified	2026-10-26

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-27 09:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

apache mina UPGRADE

Affected: >= 2.0.0 and < 2.0.28 · >= 2.1.0 and < 2.1.11 · >= 2.2.0 and < 2.2.6

Fixed in: 2.0.28, 2.1.11, 2.2.6

Safe to downgrade to: a release before 2.0.0

1. Check installed version

apt-cache policy mina || rpm -q mina || mina --version

2. UPGRADE to 2.0.28 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mina

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mina

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison mina sudo apt install mina=<VERSION_BEFORE_2.0.0> sudo apt-mark hold mina

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mina sudo dnf downgrade mina-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add mina

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Maven · org.apache.mina:mina-core · FIXED · 2.0.28 · vulnerable: >= 2.0.0, < 2.0.28 · source

Set org.apache.mina:mina-core to 2.0.28 or later in pom.xml or build.gradle, then rebuild and redeploy.

Fedora ELN · openbao · FIXED · 2.6.5-1.eln159 · FEDORA-2026-77adf886ae · source

sudo dnf upgrade --advisory=FEDORA-2026-77adf886ae

Fedora 46 · sugar-turtleart · FIXED · 220-16.fc46 · FEDORA-2026-b79483c788 · source

sudo dnf upgrade --advisory=FEDORA-2026-b79483c788

Debian 12 · mina · NO FIX YET

Debian 12 · mina2 · NO FIX YET

Debian 13 · mina2 · NO FIX YET

RHEL 8 · javapackages-tools:201801/maven-wagon · NOT AFFECTED

RHEL 9 · maven:3.9/maven-wagon · NOT AFFECTED

RHEL 9 · maven-wagon · NOT AFFECTED

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41635?

mina: upgrade to 2.0.28, 2.1.11, 2.2.6. Exact commands for each OS are on this page.

Is CVE-2026-41635 being exploited?

CVE-2026-41635 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41635 affect?

CVE-2026-41635 affects mina. Severity is critical (CVSS 9.8). Apache MINA's AbstractIoBuffer.resolveClass() contains two branches, one of them (for static classes or primitive types) does not check the class at all, bypassing the classname allowlist and allowing arbitrary code to be executed. The

How urgent is CVE-2026-41635?

Priority 60/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2026-42779 CRITICAL 9.8 UPGRADE The fix for CVE-2026-41635 was not applied to the 2.1.X and 2.2.X branches
CVE-2026-42778 CRITICAL 9.8 UPGRADE The fix for CVE-2026-41409 was not applied to the 2.1.X and 2.2.X branches
CVE-2026-41409 CRITICAL 9.8 UPGRADE The fix for CVE-2024-52046 in Apache MINA AbstractIoBuffer.getObject() was incomplete

References

← Back to latest CVEs