CVE-2016-10937: IMAPFilter through 2.6.12 does not validate the hostname in an SSL certificate.

This month

HIGH 7.5REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2016-10937 is a high-severity flaw (CVSS 7.5) affecting imapfilter, debian linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IMAPFilter through 2.6.12 does not validate the hostname in an SSL certificate.

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	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-295
Published	2019-09-08
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · fedoraproject · imapfilter project · opensuse

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

Am I affected?

Timeline

2019-09-08 16:15 UTCPublished CVE record published
2026-06-17 00:40 UTCUpdated Record last modified

imapfilter project imapfilter UPGRADE

Affected: <= 2.6.12

Fixed in: newer than 2.6.12

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.6.12 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade imapfilter

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

debian debian linux MITIGATE

Affected: 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

fedoraproject fedora MITIGATE

Affected: 30 · 31

Fixed in: no fixed release known

Safe to downgrade to: a release before 30

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.

opensuse backports sle DOWNGRADE

Affected: 15.0 sp1

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy backports-sle || rpm -q backports-sle || backports-sle --version

2. No fixed release: DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison backports-sle sudo apt install backports-sle=<VERSION_BEFORE_15.0> sudo apt-mark hold backports-sle

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

dnf --showduplicates list backports-sle sudo dnf downgrade backports-sle-<VERSION_BEFORE_15.0> sudo dnf versionlock add backports-sle

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.

opensuse leap MITIGATE

Affected: 15.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

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-2016-10937?

imapfilter: upgrade to newer than 2.6.12; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-10937 being exploited?

CVE-2016-10937 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-2016-10937 affect?

CVE-2016-10937 affects imapfilter, debian linux, fedora. Severity is high (CVSS 7.5). IMAPFilter through 2.6.12 does not validate the hostname in an SSL certificate.

How urgent is CVE-2016-10937?

Priority 52/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities

References

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