CVE-2020-11896: The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Q: How do I fix CVE-2020-11896?

tcp\/ip: upgrade to 6.0.1.66. Exact commands for each OS are on this page.

Q: Is CVE-2020-11896 being exploited?

CVE-2020-11896 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-2020-11896 affect?

CVE-2020-11896 affects tcp\/ip. Severity is critical (CVSS 10.0). The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Q: How urgent is CVE-2020-11896?

Priority 70/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 10.0REMOTEUPGRADE

CVE-2020-11896 is a critical-severity flaw (CVSS 10.0) affecting tcp\/ip. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	36.9% (top 1%)
CISA exploited list	No
Weakness	CWE-119, CWE-787
Published	2020-06-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: treck

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

Am I affected?

Timeline

2020-06-17 11:15 UTCPublished CVE record published
2026-06-17 02:51 UTCUpdated Record last modified

treck tcp\/ip UPGRADE

Affected: < 6.0.1.66

Fixed in: 6.0.1.66

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 6.0.1.66 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tcpip

Note

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

Exact fixes by distribution

Fedora 46 · nodejs-pnpm12 · FIXED · 12.17.0-1.fc46 · FEDORA-2026-7adfb2bcdd · source

sudo dnf upgrade --advisory=FEDORA-2026-7adfb2bcdd

Fedora ELN · wget2 · FIXED · 2.3.0-3.eln159 · FEDORA-2026-811b4922a5 · source

sudo dnf upgrade --advisory=FEDORA-2026-811b4922a5

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: Fans0n-Fan/Treck20-Related (10 stars)
GitHub PoC: 0xkol/ripple20-digi-connect-exploit (10 stars)
Write-up: tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-treck-ip-stack-JyBQ
Write-up: www.jsof-tech.com/ripple20/
Write-up: www.kb.cert.org/vuls/id/257161

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-2020-11896?

tcp\/ip: upgrade to 6.0.1.66. Exact commands for each OS are on this page.

Is CVE-2020-11896 being exploited?

CVE-2020-11896 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-2020-11896 affect?

CVE-2020-11896 affects tcp\/ip. Severity is critical (CVSS 10.0). The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

How urgent is CVE-2020-11896?

Priority 70/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2020-25066 CRITICAL 10.0 UPGRADE A heap-based buffer overflow in the Treck HTTP Server component before 6.0.1.68 allows remote attackers to cau
CVE-2020-11914 MEDIUM 4.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has an ARP Out-of-bounds Read.
CVE-2020-11913 MEDIUM 5.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.
CVE-2020-11912 MEDIUM 5.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has a TCP Out-of-bounds Read.
CVE-2020-11911 MEDIUM 5.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has Improper ICMPv4 Access Control.

References

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