CVE-2022-36944: Scala 2.13.x before 2.13.9 has a Java deserialization chain in its JAR file

Q: How do I fix CVE-2022-36944?

scala: upgrade to 2.13.9; scala-collection-compat: upgrade to 2.9.0; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2022-36944 being exploited?

CVE-2022-36944 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-2022-36944 affect?

CVE-2022-36944 affects scala, scala-collection-compat, fedora. Severity is critical (CVSS 9.8). Scala 2.13.x before 2.13.9 has a Java deserialization chain in its JAR file. On its own, it cannot be exploited. There is only a risk in conjunction with Java object deserialization within an application. In such situations, it allows attac

Q: How urgent is CVE-2022-36944?

Priority 71/100. Critical severity; EPSS top 4%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADEUPGRADEMITIGATE

CVE-2022-36944 is a critical-severity flaw (CVSS 9.8) affecting scala, scala-collection-compat, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Scala 2.13.x before 2.13.9 has a Java deserialization chain in its JAR file. On its own, it cannot be exploited. There is only a risk in conjunction with Java object deserialization within an application. In such situations, it allows attackers to erase contents of arbitrary files, make network connections, or possibly run arbitrary code (specifically, Function0 functions) via a gadget chain.

Why this priority

Critical severity
EPSS top 4%: very likely to be exploited
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

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	11.0% (top 4%)
CISA exploited list	No
Weakness	CWE-502
Published	2022-09-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: fedoraproject · scala-lang

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-09-23 18:15 UTCPublished CVE record published
2026-06-17 04:54 UTCUpdated Record last modified

scala-lang scala UPGRADE

Affected: >= 2.13.0 and < 2.13.9

Fixed in: 2.13.9

Safe to downgrade to: a release before 2.13.0

1. Check installed version

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

2. UPGRADE to 2.13.9 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade scala

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 2.13.0 (Debian / Ubuntu)

apt-cache madison scala sudo apt install scala=<VERSION_BEFORE_2.13.0> sudo apt-mark hold scala

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

dnf --showduplicates list scala sudo dnf downgrade scala-<VERSION_BEFORE_2.13.0> sudo dnf versionlock add scala

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.

scala-lang scala-collection-compat UPGRADE

Affected: < 2.9.0

Fixed in: 2.9.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy scala-collection-compat || rpm -q scala-collection-compat || scala-collection-compat --version

2. UPGRADE to 2.9.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade scala-collection-compat

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade scala-collection-compat

Note

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

fedoraproject fedora MITIGATE

Affected: 35 · 36

Fixed in: no fixed release known

Safe to downgrade to: a release before 35

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Maven · org.scala-lang:scala-library · FIXED · 2.13.9 · vulnerable: >= 2.13.0, < 2.13.9 · source

Set org.scala-lang:scala-library to 2.13.9 or later in pom.xml or build.gradle, then rebuild and redeploy.

Fedora 46 · iodine · FIXED · 0.9.0-2.fc46 · FEDORA-2026-4448545972 · source

sudo dnf upgrade --advisory=FEDORA-2026-4448545972

Fedora ELN · python-idna · FIXED · 3.20-1.eln159 · FEDORA-2026-4421e6642f · source

sudo dnf upgrade --advisory=FEDORA-2026-4421e6642f

Ubuntu 24.04 · scala · NOT AFFECTED

Ubuntu 20.04 · scala · NOT AFFECTED

Ubuntu 22.04 · scala · NOT AFFECTED

Ubuntu 25.04 · scala · NOT AFFECTED

Debian 12 · scala · NOT AFFECTED

Debian 13 · scala · NOT AFFECTED

RHEL 8 · scala · NO FIX YET

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: yarocher/lazylist-cve-poc (11 stars)

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-2022-36944?

scala: upgrade to 2.13.9; scala-collection-compat: upgrade to 2.9.0; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-36944 being exploited?

CVE-2022-36944 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-2022-36944 affect?

CVE-2022-36944 affects scala, scala-collection-compat, fedora. Severity is critical (CVSS 9.8). Scala 2.13.x before 2.13.9 has a Java deserialization chain in its JAR file. On its own, it cannot be exploited. There is only a risk in conjunction with Java object deserialization within an application. In such situations, it allows attac

How urgent is CVE-2022-36944?

Priority 71/100. Critical severity; EPSS top 4%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

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References

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