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GHSA-3fcv-jvfp-m4q9 BIT-cilium-2026-49445 BIT-cilium-operator-2026-49445 BIT-hubble-relay-2026-49445 CVE-2026-49445 GO-2026-5905

Cilium vulnerable to sensitive information disclosure and cluster disruption via local Envoy admin socket access

High Go
Severity
9.2 / 10
High · CVSS 3.1
Exploit chance (EPSS)
0.17%
Chance of exploitation in the next 30 days. Higher than 5.79% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-862 Missing Authorization
Fix
1.19.2
Upgrade github.com/cilium/cilium to this version or later

Description

Impact

When Cilium L7 functionality is enabled on a cluster, the Envoy instance supporting this functionality creates a world-accessible socket on cluster nodes. A local attacker would be able to access Envoy admin endpoints. Depending on deployment configuration, this can expose sensitive information or allow disruptive administrative operations, such as:

  • Exposing TLS secrets
  • Disrupting traffic in the cluster
  • Terminating the Envoy process

This issue affects both the embedded and standalone Envoy deployment models.

Patches

This issue affects:

  • Cilium v1.19 between v1.19.0 and v1.19.1 inclusive
  • Cilium v1.18 between v1.18.0 and v1.18.7 inclusive
  • All versions of Cilium prior to v1.17.14

This issue has been patched in https://github.com/cilium/cilium/pull/44512, included in:

  • Cilium v1.19.2
  • Cilium v1.18.8
  • Cilium v1.17.14

Workarounds

There is no known workaround to this issue.

Acknowledgements

The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to moemen for reporting the issue and 0xch4z for their work on triaging and remediating this issue.

For more information

If there are any questions or comments about this advisory, please reach out on [Slack (https://docs.cilium.io/en/latest/community/community/).

If anyone thinks they have found a vulnerability affecting Cilium, it is strongly encouraged to report it to the security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and the report will be treated as a top priority.

Affected versions

Go

PackageVulnerableFixed in
github.com/cilium/cilium
>= 1.19.0, < 1.19.2
1.19.2
github.com/cilium/cilium
>= 1.18.0, < 1.18.8
1.18.8
github.com/cilium/cilium
< 1.17.14
1.17.14
github.com/cilium/cilium
< 1.17.14
>= 1.18.0, < 1.18.8
>= 1.19.0, < 1.19.2
1.17.14
1.18.8
1.19.2

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/cilium/cilium Go → 1.19.2

go
go get github.com/cilium/cilium@v1.19.2 && go mod tidy

Severity breakdown

CVSS 3.1 9.2

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

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
High

Weakness

CWE-862: Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

How to prevent it
  • Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
  • Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
  • System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-fm8w-2m5w-9j7r
Cilium may unexpectedly allow ingress traffic from the local namespace when a Kubernetes NetworkPolicy is configured with an ipBlock match
Medium Also affects github.com/cilium/cilium
GHSA-w7c2-w76w-5hmj
Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
High Also affects github.com/cilium/cilium
GHSA-q6h5-q3q6-f87x
CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation
Medium Also affects github.com/cilium/cilium
GHSA-gj49-89wh-h4gj
Cillium exposes sensitive information included in the cilium-bugtool debug archive
Medium Also affects github.com/cilium/cilium
GHSA-hxv8-4j4r-cqgv
Cilium L7 proxy may bypass Kubernetes NetworkPolicy for same-node traffic
Medium Also affects github.com/cilium/cilium
GHSA-5r23-prx4-mqg3
Cilium may not enforce host firewall policies when Native Routing, WireGuard and Node Encryption are enabled
Medium Also affects github.com/cilium/cilium
GHSA-38pp-6gcp-rqvm
Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic
Medium Also affects github.com/cilium/cilium
GHSA-5vxx-c285-pcq4
In Cilium, packets from terminating endpoints may not be encrypted in Wireguard-enabled clusters
Medium Also affects github.com/cilium/cilium
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