CVE-2017-5334: Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before 3.3.26 and 3.5.x befor

Q: How do I fix CVE-2017-5334?

leap: mitigate or apply the listed mitigation; gnutls: upgrade to newer than 3.3.25. Exact commands for each OS are on this page.

Q: Is CVE-2017-5334 being exploited?

CVE-2017-5334 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-2017-5334 affect?

CVE-2017-5334 affects leap, gnutls. Severity is critical (CVSS 9.8). Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows remote attackers to have unspecified impact via crafted policy language information in an X.509 certificate with a

Q: How urgent is CVE-2017-5334?

Priority 69/100. Critical severity; EPSS top 2%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.8REMOTEWATCHLISTMITIGATEUPGRADE

CVE-2017-5334 is a critical-severity flaw (CVSS 9.8) affecting leap, gnutls. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows remote attackers to have unspecified impact via crafted policy language information in an X.509 certificate with a Proxy Certificate Information extension.

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
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	32.8% (top 2%)
CISA exploited list	No
Weakness	CWE-415
Published	2017-03-24
Last modified	2026-06-17

Publisher (CNA): Debian GNU/Linux · Vendor: gnu · opensuse

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

Am I affected?

Timeline

2017-03-24 15:59 UTCPublished CVE record published
2026-06-17 01:20 UTCUpdated Record last modified

opensuse leap MITIGATE

Affected: 42.1 · 42.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 42.1

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.

gnu gnutls UPGRADE

Affected: <= 3.3.25 · 3.5.0 · 3.5.1 · 3.5.2 · 3.5.3 · 3.5.4 · 3.5.5 · 3.5.6

Fixed in: newer than 3.3.25

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 3.3.25 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gnutls

Note

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

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora ELN · fuse-sshfs · FIXED · 3.7.6-3.eln159 · FEDORA-2026-bcb7be7c5c · source

sudo dnf upgrade --advisory=FEDORA-2026-bcb7be7c5c

Fedora 46 · python-odata-query · FIXED · 0.10.1-1.fc46 · FEDORA-2026-eab44dc513 · source

sudo dnf upgrade --advisory=FEDORA-2026-eab44dc513

Debian 12 · gnutls28 · FIXED · 3.5.8-1

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.5.8-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · gnutls28 · FIXED · 3.5.8-1

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.5.8-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 7 · gnutls · FIXED · gnutls-3.3.26-9.el7

sudo dnf upgrade --advisory=RHSA-2017:2292 rpm -q gnutls

RHEL 5 · gnutls · NOT AFFECTED

RHEL 6 · gnutls · NOT AFFECTED

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-2017-5334?

leap: mitigate or apply the listed mitigation; gnutls: upgrade to newer than 3.3.25. Exact commands for each OS are on this page.

Is CVE-2017-5334 being exploited?

CVE-2017-5334 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-2017-5334 affect?

CVE-2017-5334 affects leap, gnutls. Severity is critical (CVSS 9.8). Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows remote attackers to have unspecified impact via crafted policy language information in an X.509 certificate with a

How urgent is CVE-2017-5334?

Priority 69/100. Critical severity; EPSS top 2%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

GnuTLS vulnerabilities

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References

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