CVE-2026-19654: A unauthenticated remote peer may lead rsyslogd to crash due to a flaw in the optional imptcp module

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HIGH 7.5REMOTEWATCHLISTUPGRADEMITIGATE

CVE-2026-19654 is a high-severity flaw (CVSS 7.5) affecting rsyslog, enterprise linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A unauthenticated remote peer may lead rsyslogd to crash due to a flaw in the optional imptcp module. A crafted input sequence during oversize-frame recovery can cause an invalid internal message length and terminate rsyslogd. No confidentiality or integrity impact, privilege escalation, or code execution has been identified. imtcp and the default imptcp framing modes are not affected.

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

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 53%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-08-12
Last modified	2026-10-21

Publisher (CNA): Red Hat, Inc. · Vendor: redhat · rsyslog

Last updated 2026-10-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-12 21:17 UTCPublished CVE record published
2026-10-21 21:17 UTCUpdated Record last modified

rsyslog rsyslog UPGRADE

Affected: >= 8.36.0 and < 8.2608.0

Fixed in: 8.2608.0

Safe to downgrade to: a release before 8.36.0

1. Check installed version

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

2. UPGRADE to 8.2608.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade rsyslog

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 8.36.0 (Debian / Ubuntu)

apt-cache madison rsyslog sudo apt install rsyslog=<VERSION_BEFORE_8.36.0> sudo apt-mark hold rsyslog

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

dnf --showduplicates list rsyslog sudo dnf downgrade rsyslog-<VERSION_BEFORE_8.36.0> sudo dnf versionlock add rsyslog

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.

redhat enterprise linux MITIGATE

Affected: 6.0 · 7.0 · 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

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.

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-2026-19654?

rsyslog: upgrade to 8.2608.0; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-19654 being exploited?

CVE-2026-19654 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-2026-19654 affect?

CVE-2026-19654 affects rsyslog, enterprise linux. Severity is high (CVSS 7.5). A unauthenticated remote peer may lead rsyslogd to crash due to a flaw in the optional imptcp module. A crafted input sequence during oversize-frame recovery can cause an invalid internal message length and terminate rsyslogd. No confidenti

How urgent is CVE-2026-19654?

Priority 48/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

References

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