CVE-2023-31442: In Lightbend Akka before 2.8.1, the async-dns resolver (used by Discovery in DNS mode and transitively by Clus

Q: How do I fix CVE-2023-31442?

akka actor: upgrade to 2.8.1; akka discovery: upgrade to 2.8.1. Exact commands for each OS are on this page.

Q: Is CVE-2023-31442 being exploited?

CVE-2023-31442 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-2023-31442 affect?

CVE-2023-31442 affects akka actor, akka discovery. Severity is high (CVSS 7.5). In Lightbend Akka before 2.8.1, the async-dns resolver (used by Discovery in DNS mode and transitively by Cluster Bootstrap) uses predictable DNS transaction IDs when resolving DNS records, making DNS resolution subject to poisoning by an a

Q: How urgent is CVE-2023-31442?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADEUPGRADE

CVE-2023-31442 is a high-severity flaw (CVSS 7.5) affecting akka actor, akka discovery. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Lightbend Akka before 2.8.1, the async-dns resolver (used by Discovery in DNS mode and transitively by Cluster Bootstrap) uses predictable DNS transaction IDs when resolving DNS records, making DNS resolution subject to poisoning by an attacker. If the application performing discovery does not validate (e.g., via TLS) the authenticity of the discovered service, this may result in exfiltration of application data (e.g., persistence events may b

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 49%)
CISA exploited list	No
Published	2023-05-11
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: lightbend

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

Am I affected?

Timeline

2023-05-11 02:15 UTCPublished CVE record published
2026-06-17 05:56 UTCUpdated Record last modified

lightbend akka actor UPGRADE

Affected: >= 2.5.14 and < 2.8.1

Fixed in: 2.8.1

Safe to downgrade to: a release before 2.5.14

1. Check installed version

apt-cache policy akka-actor || rpm -q akka-actor || akka-actor --version

2. UPGRADE to 2.8.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade akka-actor

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade akka-actor

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 2.5.14 (Debian / Ubuntu)

apt-cache madison akka-actor sudo apt install akka-actor=<VERSION_BEFORE_2.5.14> sudo apt-mark hold akka-actor

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

dnf --showduplicates list akka-actor sudo dnf downgrade akka-actor-<VERSION_BEFORE_2.5.14> sudo dnf versionlock add akka-actor

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.

lightbend akka discovery UPGRADE

Affected: < 2.8.1

Fixed in: 2.8.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy akka-discovery || rpm -q akka-discovery || akka-discovery --version

2. UPGRADE to 2.8.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade akka-discovery

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade akka-discovery

Note

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

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-2023-31442?

akka actor: upgrade to 2.8.1; akka discovery: upgrade to 2.8.1. Exact commands for each OS are on this page.

Is CVE-2023-31442 being exploited?

CVE-2023-31442 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-2023-31442 affect?

CVE-2023-31442 affects akka actor, akka discovery. Severity is high (CVSS 7.5). In Lightbend Akka before 2.8.1, the async-dns resolver (used by Discovery in DNS mode and transitively by Cluster Bootstrap) uses predictable DNS transaction IDs when resolving DNS records, making DNS resolution subject to poisoning by an a

How urgent is CVE-2023-31442?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

Software pages

Bootstrap vulnerabilities

References

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