CVE-2023-50784: A buffer overflow in websockets in UnrealIRCd 6.1.0 through 6.1.3 before 6.1.4 allows an unauthenticated remot

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HIGH 7.5REMOTEUPGRADE

CVE-2023-50784 is a high-severity flaw (CVSS 7.5) affecting unrealircd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A buffer overflow in websockets in UnrealIRCd 6.1.0 through 6.1.3 before 6.1.4 allows an unauthenticated remote attacker to crash the server by sending an oversized packet (if a websocket port is open). Remote code execution might be possible on some uncommon, older platforms.

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	1.9% (top 20%)
CISA exploited list	No
Weakness	CWE-120
Published	2023-12-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: unrealircd

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

Am I affected?

Timeline

2023-12-16 23:15 UTCPublished CVE record published
2026-06-17 06:39 UTCUpdated Record last modified

unrealircd unrealircd UPGRADE

Affected: >= 6.1.0 and < 6.1.4

Fixed in: 6.1.4

Safe to downgrade to: a release before 6.1.0

1. Check installed version

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

2. UPGRADE to 6.1.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade unrealircd

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 6.1.0 (Debian / Ubuntu)

apt-cache madison unrealircd sudo apt install unrealircd=<VERSION_BEFORE_6.1.0> sudo apt-mark hold unrealircd

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

dnf --showduplicates list unrealircd sudo dnf downgrade unrealircd-<VERSION_BEFORE_6.1.0> sudo dnf versionlock add unrealircd

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-2023-50784?

unrealircd: upgrade to 6.1.4. Exact commands for each OS are on this page.

Is CVE-2023-50784 being exploited?

CVE-2023-50784 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-2023-50784 affect?

CVE-2023-50784 affects unrealircd. Severity is high (CVSS 7.5). A buffer overflow in websockets in UnrealIRCd 6.1.0 through 6.1.3 before 6.1.4 allows an unauthenticated remote attacker to crash the server by sending an oversized packet (if a websocket port is open). Remote code execution might be possib

How urgent is CVE-2023-50784?

Priority 51/100. High severity; Remotely exploitable, no login, no user action

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References

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