CVE-2017-12588: The zmq3 input and output modules in rsyslog before 8.28.0 interpreted description fields as format strings, p

Q: How do I fix CVE-2017-12588?

rsyslog: upgrade to newer than 8.27.0. Exact commands for each OS are on this page.

Q: Is CVE-2017-12588 being exploited?

CVE-2017-12588 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-2017-12588 affect?

CVE-2017-12588 affects rsyslog. Severity is critical (CVSS 9.8). The zmq3 input and output modules in rsyslog before 8.28.0 interpreted description fields as format strings, possibly allowing a format string attack with unspecified impact.

Q: How urgent is CVE-2017-12588?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2017-12588 is a critical-severity flaw (CVSS 9.8) affecting rsyslog. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The zmq3 input and output modules in rsyslog before 8.28.0 interpreted description fields as format strings, possibly allowing a format string attack with unspecified impact.

Why this priority

Critical severity
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	2.8% (top 13%)
CISA exploited list	No
Weakness	CWE-134
Published	2017-08-06
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: rsyslog

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

Am I affected?

Timeline

2017-08-06 14:29 UTCPublished CVE record published
2026-06-17 01:03 UTCUpdated Record last modified

rsyslog rsyslog UPGRADE

Affected: <= 8.27.0

Fixed in: newer than 8.27.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 8.27.0 (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.

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-2017-12588?

rsyslog: upgrade to newer than 8.27.0. Exact commands for each OS are on this page.

Is CVE-2017-12588 being exploited?

CVE-2017-12588 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-2017-12588 affect?

CVE-2017-12588 affects rsyslog. Severity is critical (CVSS 9.8). The zmq3 input and output modules in rsyslog before 8.28.0 interpreted description fields as format strings, possibly allowing a format string attack with unspecified impact.

How urgent is CVE-2017-12588?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-19654 HIGH 7.5 UPGRADE MITIGATE A unauthenticated remote peer may lead rsyslogd to crash due to a flaw in the optional imptcp module
CVE-2019-17042 CRITICAL 9.8 DOWNGRADE MITIGATE An issue was discovered in Rsyslog v8.1908.0
CVE-2019-17041 CRITICAL 9.8 DOWNGRADE MITIGATE An issue was discovered in Rsyslog v8.1908.0
CVE-2019-17040 CRITICAL 9.8 DOWNGRADE contrib/pmdb2diag/pmdb2diag.c in Rsyslog v8.1908.0 allows out-of-bounds access because the level length is mis
CVE-2018-16881 HIGH 7.5 UPGRADE DOWNGRADE A denial of service vulnerability was found in rsyslog in the imptcp module

References

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