CVE-2020-10749 [Medium] | Security Vulnerability in Cni Network Plugins

A vulnerability was found in all versions of containernetworking/plugins before version 0.8.6, that allows malicious containers in Kubernetes clusters to perform man-in-the-middle (MitM) attacks. A malicious container can exploit this flaw by sending rogue IPv6 router advertisements to the host or other containers, to redirect traffic to the malicious container.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	1.84%	2.41%	+0.57%
2	2026-06-01	2.18%	1.84%	-0.34%
3	2026-05-28	—	2.18%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

1.84%

2.41%

+0.57%

2026-06-01

2.18%

1.84%

-0.34%

2026-05-28

—

2.18%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.0	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	1.8	3.7	[email protected]
6.0	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	1.8	3.7	[email protected]
6.0	2.0	MEDIUM	`AV:N/AC:M/Au:S/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	6.8	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.0

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

1.8

3.7

[email protected]

6.0

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

1.8

3.7

[email protected]

6.0

2.0

MEDIUM

AV:N/AC:M/Au:S/C:P/I:P/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

6.8

6.4

[email protected]

OS Trackers for CVE-2020-10749

vendor	priority	summary	link
`alpine`	medium	CVE-2020-10749: 1 source package rows (k3s); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0.	https://security.alpinelinux.org/vuln/CVE-2020-10749
`debian`	not yet assigned	CVE-2020-10749 not yet assigned priority: Debian including 1 source packages (golang-github-containernetworking-plugins), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2020-10749
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2020-10749
`suse`	medium	CVE-2020-10749 severity moderate: SUSE including 40 source package names (1.6.6:cni-plugins-0.8.6-3.6.1, buildah-1.15.1-2.module+el8.3.0+8221+97165c3f, …), 50 product×package rows across 24 product lines (Container caasp/v4/cilium, Container rancher/elemental-teal-rt/5.4, … (24 product lines)): Fixed 50.	https://www.suse.com/security/cve/CVE-2020-10749/
`ubuntu`	medium	CVE-2020-10749 medium priority: Ubuntu including 1 source packages (golang-github-containernetworking-plugins), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 11, DNE 4, needs-triage 2.	https://ubuntu.com/security/CVE-2020-10749

Affected software / configurations for CVE-2020-10749

Vendor	Product	Version	Raw CPE
linuxfoundation	cni_network_plugins	< 0.8.6	cpe:2.3:a:linuxfoundation:cni_network_plugins::::::::
redhat	openshift_container_platform	4.0	cpe:2.3:a:redhat:openshift_container_platform:4.0:::::::*
fedoraproject	fedora	32	cpe:2.3:o:fedoraproject:fedora:32:::::::*
redhat	enterprise_linux	7.0	cpe:2.3:o:redhat:enterprise_linux:7.0:::::::*
redhat	enterprise_linux	8.0	cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*

References for CVE-2020-10749

URL	Tags
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00063.html	Broken Link Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00065.html	Broken Link Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10749	Issue Tracking Third Party Advisory
https://groups.google.com/forum/#%21topic/kubernetes-security-announce/BMb_6ICCfp8
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DV3HCDZYUTPPVDUMTZXDKK6IUO3JMGJC/

URL

CVE-2020-10749

Exploit prediction scoring system (EPSS) score for CVE-2020-10749

Common vulnerability scoring system (CVSS) metrics for CVE-2020-10749

Weakness enumeration for CVE-2020-10749

GitHub Security Advisory for CVE-2020-10749

OS Trackers for CVE-2020-10749

Affected software / configurations for CVE-2020-10749

References for CVE-2020-10749