CVE-2024-23649: Lemmy is a link aggregator and forum for the fediverse

This month

HIGH 7.5REMOTEUPGRADE

CVE-2024-23649 is a high-severity flaw (CVSS 7.5) affecting lemmy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Lemmy is a link aggregator and forum for the fediverse. Starting in version 0.17.0 and prior to version 0.19.1, users can report private messages, even when they're neither sender nor recipient of the message. The API response to creating a private message report contains the private message itself, which means any user can just iterate over message ids to (loudly) obtain all private messages of an instance. A user with instance admin privileges

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	0.5% (top 57%)
CISA exploited list	No
Weakness	CWE-200, CWE-285
Published	2024-01-24
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: join-lemmy

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

Am I affected?

Timeline

2024-01-24 18:15 UTCPublished CVE record published
2026-06-17 07:13 UTCUpdated Record last modified

join-lemmy lemmy UPGRADE

Affected: >= 0.17.0 and < 0.19.1

Fixed in: 0.19.1

Safe to downgrade to: a release before 0.17.0

1. Check installed version

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

2. UPGRADE to 0.19.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade lemmy

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 0.17.0 (Debian / Ubuntu)

apt-cache madison lemmy sudo apt install lemmy=<VERSION_BEFORE_0.17.0> sudo apt-mark hold lemmy

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

dnf --showduplicates list lemmy sudo dnf downgrade lemmy-<VERSION_BEFORE_0.17.0> sudo dnf versionlock add lemmy

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.

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-2024-23649?

lemmy: upgrade to 0.19.1. Exact commands for each OS are on this page.

Is CVE-2024-23649 being exploited?

CVE-2024-23649 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-2024-23649 affect?

CVE-2024-23649 affects lemmy. Severity is high (CVSS 7.5). Lemmy is a link aggregator and forum for the fediverse. Starting in version 0.17.0 and prior to version 0.19.1, users can report private messages, even when they're neither sender nor recipient of the message. The API response to creating a

How urgent is CVE-2024-23649?

Priority 42/100. High severity; Remotely exploitable, no login, no user action

References

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