CVE-2003-0686: Buffer overflow in PAM SMB module (pam_smb) 1.1.6 and earlier, when authenticating to a remote service, allows

Q: How do I fix CVE-2003-0686?

pam smb: downgrade or apply the listed mitigation; pam smb: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2003-0686 being exploited?

CVE-2003-0686 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-2003-0686 affect?

CVE-2003-0686 affects pam smb, pam smb. Severity is high (CVSS 7.5). Buffer overflow in PAM SMB module (pam_smb) 1.1.6 and earlier, when authenticating to a remote service, allows remote attackers to execute arbitrary code.

Q: How urgent is CVE-2003-0686?

Priority 61/100. High severity; EPSS top 2%: very likely to be exploited; Public exploit reference; On your watchlist

This week

HIGH 7.5WATCHLISTDOWNGRADEDOWNGRADE

CVE-2003-0686 is a high-severity flaw (CVSS 7.5) affecting pam smb, pam smb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in PAM SMB module (pam_smb) 1.1.6 and earlier, when authenticating to a remote service, allows remote attackers to execute arbitrary code.

Why this priority

High severity
EPSS top 2%: very likely to be exploited
Public exploit reference
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	27.0% (top 2%)
CISA exploited list	No
Published	2003-10-20
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: dave airlie · redhat

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2003-10-20 04:00 UTCPublished CVE record published
2026-06-16 22:02 UTCUpdated Record last modified

dave airlie pam smb DOWNGRADE

Affected: 1.1 · 1.1.1 · 1.1.2 · 1.1.3 · 1.1.4 · 1.1.5 · 1.1.6 · 2.0_rc4

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.1

1. Check installed version

apt-cache policy pam-smb || rpm -q pam-smb || pam-smb --version

2. No fixed release: DOWNGRADE to a release before 1.1 (Debian / Ubuntu)

apt-cache madison pam-smb sudo apt install pam-smb=<VERSION_BEFORE_1.1> sudo apt-mark hold pam-smb

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pam-smb sudo dnf downgrade pam-smb-<VERSION_BEFORE_1.1> sudo dnf versionlock add pam-smb

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 pam smb DOWNGRADE

Affected: 1.1.6-2 · 1.1.6-5 · 1.1.6-7

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.1.6-2

1. Check installed version

apt-cache policy pam-smb || rpm -q pam-smb || pam-smb --version

2. No fixed release: DOWNGRADE to a release before 1.1.6-2 (Debian / Ubuntu)

apt-cache madison pam-smb sudo apt install pam-smb=<VERSION_BEFORE_1.1.6-2> sudo apt-mark hold pam-smb

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pam-smb sudo dnf downgrade pam-smb-<VERSION_BEFORE_1.1.6-2> sudo dnf versionlock add pam-smb

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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Linux pam_lib_smb < 1.1.6 - '/bin/login' Remote Overflow

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-2003-0686?

pam smb: downgrade or apply the listed mitigation; pam smb: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2003-0686 being exploited?

CVE-2003-0686 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-2003-0686 affect?

CVE-2003-0686 affects pam smb, pam smb. Severity is high (CVSS 7.5). Buffer overflow in PAM SMB module (pam_smb) 1.1.6 and earlier, when authenticating to a remote service, allows remote attackers to execute arbitrary code.

How urgent is CVE-2003-0686?

Priority 61/100. High severity; EPSS top 2%: very likely to be exploited; Public exploit reference; On your watchlist

Related CVEs

CVE-2000-0843 HIGH 10.0 DOWNGRADE DOWNGRADE Buffer overflow in pam_smb and pam_ntdom pluggable authentication modules (PAM) allow remote attackers to exec

References

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