CVE-2018-7750: transport.py in the SSH server implementation of Paramiko before 1.17.6, 1.18.x before 1.18.5, 2.0.x before 2.

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADEDOWNGRADEDOWNGRADE

CVE-2018-7750 is a critical-severity flaw (CVSS 9.8) affecting paramiko, ansible engine, cloudforms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

transport.py in the SSH server implementation of Paramiko before 1.17.6, 1.18.x before 1.18.5, 2.0.x before 2.0.8, 2.1.x before 2.1.5, 2.2.x before 2.2.3, 2.3.x before 2.3.2, and 2.4.x before 2.4.1 does not properly check whether authentication is completed before processing other requests, as demonstrated by channel-open. A customized SSH client can simply skip the authentication step.

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

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	27.1% (top 2%)
CISA exploited list	No
Weakness	CWE-287
Published	2018-03-13
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: paramiko · redhat

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

Am I affected?

Timeline

2018-03-13 18:29 UTCPublished CVE record published
2026-06-17 02:03 UTCUpdated Record last modified

paramiko paramiko UPGRADE

Affected: < 1.17.6 · >= 1.18.0 and < 1.18.5 · >= 2.0.0 and < 2.0.8 · >= 2.1.0 and < 2.1.5 · >= 2.2.0 and < 2.2.3 · >= 2.3.0 and < 2.3.2 · 2.4.0

Fixed in: 1.17.6, 1.18.5, 2.0.8, 2.1.5, 2.2.3, 2.3.2

Safe to downgrade to: a release before 1.18.0

1. Check installed version

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

2. UPGRADE to 1.17.6 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade paramiko

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 1.18.0 (Debian / Ubuntu)

apt-cache madison paramiko sudo apt install paramiko=<VERSION_BEFORE_1.18.0> sudo apt-mark hold paramiko

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

dnf --showduplicates list paramiko sudo dnf downgrade paramiko-<VERSION_BEFORE_1.18.0> sudo dnf versionlock add paramiko

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 ansible engine DOWNGRADE

Affected: 2.0 · 2.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

apt-cache policy ansible-engine || rpm -q ansible-engine || ansible-engine --version

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison ansible-engine sudo apt install ansible-engine=<VERSION_BEFORE_2.0> sudo apt-mark hold ansible-engine

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

dnf --showduplicates list ansible-engine sudo dnf downgrade ansible-engine-<VERSION_BEFORE_2.0> sudo dnf versionlock add ansible-engine

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 cloudforms DOWNGRADE

Affected: 4.5 · 4.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.5

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.5 (Debian / Ubuntu)

apt-cache madison cloudforms sudo apt install cloudforms=<VERSION_BEFORE_4.5> sudo apt-mark hold cloudforms

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

dnf --showduplicates list cloudforms sudo dnf downgrade cloudforms-<VERSION_BEFORE_4.5> sudo dnf versionlock add cloudforms

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 virtualization DOWNGRADE

Affected: 4.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.1 (Debian / Ubuntu)

apt-cache madison virtualization sudo apt install virtualization=<VERSION_BEFORE_4.1> sudo apt-mark hold virtualization

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

dnf --showduplicates list virtualization sudo dnf downgrade virtualization-<VERSION_BEFORE_4.1> sudo dnf versionlock add virtualization

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 desktop MITIGATE

Affected: 6.0

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.

redhat enterprise linux server MITIGATE

Affected: 6.0 · 7.0

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Python (pip) · paramiko · FIXED · 2.0.8 · vulnerable: >= 2.0.0, < 2.0.8 · source

pip install --upgrade "paramiko>=2.0.8" pip show paramiko

Fedora 46 · shotcut · FIXED · 26.10.30-1.fc46 · FEDORA-2026-7787c7fc2d · source

sudo dnf upgrade --advisory=FEDORA-2026-7787c7fc2d

Debian 12 · paramiko · FIXED · 2.4.2-0.1

sudo apt update && sudo apt install --only-upgrade paramiko dpkg --compare-versions "$(dpkg-query -W -f='${Version}' paramiko)" ge "2.4.2-0.1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · paramiko · FIXED · 2.4.2-0.1

sudo apt update && sudo apt install --only-upgrade paramiko dpkg --compare-versions "$(dpkg-query -W -f='${Version}' paramiko)" ge "2.4.2-0.1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 6 · python-paramiko · FIXED · python-paramiko-1.7.5-4.el6_9

sudo dnf upgrade --advisory=RHSA-2018:1124 rpm -q python-paramiko

RHEL 6.4 Advanced Update Support · python-paramiko · FIXED · python-paramiko-1.7.5-4.el6_4

sudo dnf upgrade --advisory=RHSA-2018:1125 rpm -q python-paramiko

RHEL 6.5 Advanced Update Support · python-paramiko · FIXED · python-paramiko-1.7.5-4.el6_5

sudo dnf upgrade --advisory=RHSA-2018:1125 rpm -q python-paramiko

RHEL 6.6 Advanced Update Support · python-paramiko · FIXED · python-paramiko-1.7.5-4.el6_6

sudo dnf upgrade --advisory=RHSA-2018:1125 rpm -q python-paramiko

RHEL 6.6 Telco Extended Update Support · python-paramiko · FIXED · python-paramiko-1.7.5-4.el6_6

sudo dnf upgrade --advisory=RHSA-2018:1125 rpm -q python-paramiko

Alpine 3.20 · py3-paramiko · FIXED · py3-paramiko-2.4.1-r0

apk add --upgrade py3-paramiko apk info -v py3-paramiko

Alpine 3.21 · py3-paramiko · FIXED · py3-paramiko-2.4.1-r0

apk add --upgrade py3-paramiko apk info -v py3-paramiko

Alpine 3.22 · py3-paramiko · FIXED · py3-paramiko-2.4.1-r0

apk add --upgrade py3-paramiko apk info -v py3-paramiko

Alpine 3.23 · py3-paramiko · FIXED · py3-paramiko-2.4.1-r0

apk add --upgrade py3-paramiko apk info -v py3-paramiko

Amazon Linux 1 · see advisory · FIXED · ALAS-2018-989 · source

sudo yum update --advisory=ALAS-2018-989

Public exploits and detection

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

GitHub PoC: jm33-m0/CVE-2018-7750 (21 stars)
GitHub PoC: tlavi00/CVE-2018-7750 (0 stars)
Write-up: github.com/paramiko/paramiko/blob/master/sites/www/changelog.rst
Write-up: www.exploit-db.com/exploits/45712/
Exploit-DB: Paramiko 2.4.1 - Authentication Bypass

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-2018-7750?

paramiko: upgrade to 1.17.6, 1.18.5, 2.0.8, 2.1.5, 2.2.3, 2.3.2; ansible engine: downgrade or apply the listed mitigation; cloudforms: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-7750 being exploited?

CVE-2018-7750 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-2018-7750 affect?

CVE-2018-7750 affects paramiko, ansible engine, cloudforms. Severity is critical (CVSS 9.8). transport.py in the SSH server implementation of Paramiko before 1.17.6, 1.18.x before 1.18.5, 2.0.x before 2.0.8, 2.1.x before 2.1.5, 2.2.x before 2.2.3, 2.3.x before 2.3.2, and 2.4.x before 2.4.1 does not properly check whether authentica

How urgent is CVE-2018-7750?

Priority 74/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Ansible vulnerabilities

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CVE-2022-24302 MEDIUM 5.9 UPGRADE MITIGATE In Paramiko before 2.10.1, a race condition (between creation and chmod) in the write_private_key_file functio
CVE-2018-1000805 HIGH 8.8 DOWNGRADE DOWNGRADE Paramiko version 2.4.1, 2.3.2, 2.2.3, 2.1.5, 2.0.8, 1.18.5, 1.17.6 contains a Incorrect Access Control vulnera

References

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