VDB-347023 · CVE-2026-26963 · GHSA-5r23-prx4-mqg3

Cilium up to 1.18.5 authorization

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5.8	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Cilium up to 1.18.5. It has been classified as critical. The affected element is an unknown function. This manipulation causes authorization. This vulnerability appears as CVE-2026-26963. The attacker needs to be present on the local network. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical was found in Cilium up to 1.18.5. Affected by this vulnerability is an unknown code block. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Versions 1.18.0 through 1.18.5 will incorrectly permit traffic from Pods on other nodes when Native Routing, WireGuard and Node Encryption are enabled. This issue has been fixed in version 1.18.6.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-26963 since 02/16/2026. The exploitation appears to be easy. Access to the local network is required for this attack. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 299761 (Linux Distros Unpatched Vulnerability : CVE-2026-26963), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.18.6 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 88e28e1e62c0b1a02c3f0fc22d888ac9eefbe885 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (299761). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

Cilium

Version

License

open-source

Website

Product: https://github.com/cilium/cilium/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.4
NVD Vector: 🔒

CNA Base Score: 6.1
CNA Vector (GitHub_M): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authorization
CWE: CWE-863 / CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 299761
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-26963

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Cilium 1.18.6
Patch: 88e28e1e62c0b1a02c3f0fc22d888ac9eefbe885

Timelineinfo

02/16/2026 CVE reserved
02/20/2026 +4 days Advisory disclosed
02/20/2026 +0 days VulDB entry created
02/23/2026 +3 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-5r23-prx4-mqg3
Status: Confirmed

CVE: CVE-2026-26963 (🔒)
GCVE (CVE): GCVE-0-2026-26963
GCVE (VulDB): GCVE-100-347023

Entryinfo

Created: 02/20/2026 01:23
Updated: 02/23/2026 20:08
Changes: 02/20/2026 01:23 (65), 02/22/2026 05:41 (11), 02/23/2026 20:08 (2)
Complete: 🔍
Cache ID: 216::103