CVE-2018-16807: In Bro through 2.5.5, there is a memory leak potentially leading to DoS in scripts/base/protocols/krb/main.bro

Q: How do I fix CVE-2018-16807?

bro: upgrade to newer than 2.5.5. Exact commands for each OS are on this page.

Q: Is CVE-2018-16807 being exploited?

CVE-2018-16807 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-2018-16807 affect?

CVE-2018-16807 affects bro. Severity is high (CVSS 7.5). In Bro through 2.5.5, there is a memory leak potentially leading to DoS in scripts/base/protocols/krb/main.bro in the Kerberos protocol parser.

Q: How urgent is CVE-2018-16807?

Priority 49/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2018-16807 is a high-severity flaw (CVSS 7.5) affecting bro. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Bro through 2.5.5, there is a memory leak potentially leading to DoS in scripts/base/protocols/krb/main.bro in the Kerberos protocol parser.

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	1.4% (top 28%)
CISA exploited list	No
Weakness	CWE-772
Published	2018-09-11
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: bro

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

Am I affected?

Timeline

2018-09-11 02:29 UTCPublished CVE record published
2026-06-17 01:44 UTCUpdated Record last modified

bro bro UPGRADE

Affected: <= 2.5.5

Fixed in: newer than 2.5.5

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.5.5 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bro

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-2018-16807?

bro: upgrade to newer than 2.5.5. Exact commands for each OS are on this page.

Is CVE-2018-16807 being exploited?

CVE-2018-16807 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-2018-16807 affect?

CVE-2018-16807 affects bro. Severity is high (CVSS 7.5). In Bro through 2.5.5, there is a memory leak potentially leading to DoS in scripts/base/protocols/krb/main.bro in the Kerberos protocol parser.

How urgent is CVE-2018-16807?

Priority 49/100. High severity; Remotely exploitable, no login, no user action

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References

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