GHSA-q6h5-q3q6-f87x: CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation
A vulnerability in Cilium's CiliumLocalRedirectPolicy allows users with policy creation privileges to hijack cross-namespace service traffic by specifying arbitrary ClusterIPs via addressMatcher, bypassing namespace-scoping protections. Deleting such a malicious policy can also corrupt internal service state, disrupting service translation. This affects certain versions of Cilium prior to fixed releases. No workaround is available.
AI Analysis
Technical Summary
The vulnerability in CiliumLocalRedirectPolicy's addressMatcher component permits users authorized to create CiliumLocalRedirectPolicies to specify arbitrary ClusterIPs, enabling traffic hijacking across namespaces and bypassing namespace-scoping enforced by serviceMatcher. Additionally, removal of such a policy can corrupt Cilium's internal service state, causing service translation failures for the targeted Service. The issue affects Cilium versions 1.19.0 through 1.19.3, 1.18.2 through 1.18.9, and all versions prior to 1.17.16. Fixes have been implemented in versions 1.19.4, 1.18.10, and 1.17.16. No workaround exists.
Potential Impact
An attacker with the ability to create CiliumLocalRedirectPolicies can hijack service traffic across namespaces, violating namespace isolation guarantees. This can lead to unauthorized traffic redirection and potential denial of service by corrupting service translation when the malicious policy is deleted. The impact includes limited confidentiality loss (traffic hijacking), no integrity loss, and high availability impact (service translation disruption).
Mitigation Recommendations
Official fixes are available in Cilium versions 1.19.4, 1.18.10, and 1.17.16. Users should upgrade to these or later versions to remediate the vulnerability. There are no workarounds available. Users should restrict the ability to create CiliumLocalRedirectPolicies to trusted administrators only.
GHSA-q6h5-q3q6-f87x: CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation
Description
A vulnerability in Cilium's CiliumLocalRedirectPolicy allows users with policy creation privileges to hijack cross-namespace service traffic by specifying arbitrary ClusterIPs via addressMatcher, bypassing namespace-scoping protections. Deleting such a malicious policy can also corrupt internal service state, disrupting service translation. This affects certain versions of Cilium prior to fixed releases. No workaround is available.
CVSS v3.1
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in CiliumLocalRedirectPolicy's addressMatcher component permits users authorized to create CiliumLocalRedirectPolicies to specify arbitrary ClusterIPs, enabling traffic hijacking across namespaces and bypassing namespace-scoping enforced by serviceMatcher. Additionally, removal of such a policy can corrupt Cilium's internal service state, causing service translation failures for the targeted Service. The issue affects Cilium versions 1.19.0 through 1.19.3, 1.18.2 through 1.18.9, and all versions prior to 1.17.16. Fixes have been implemented in versions 1.19.4, 1.18.10, and 1.17.16. No workaround exists.
Potential Impact
An attacker with the ability to create CiliumLocalRedirectPolicies can hijack service traffic across namespaces, violating namespace isolation guarantees. This can lead to unauthorized traffic redirection and potential denial of service by corrupting service translation when the malicious policy is deleted. The impact includes limited confidentiality loss (traffic hijacking), no integrity loss, and high availability impact (service translation disruption).
Mitigation Recommendations
Official fixes are available in Cilium versions 1.19.4, 1.18.10, and 1.17.16. Users should upgrade to these or later versions to remediate the vulnerability. There are no workarounds available. Users should restrict the ability to create CiliumLocalRedirectPolicies to trusted administrators only.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-q6h5-q3q6-f87x
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-53935"]
- Ecosystems
- ["Go"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a4c340527e9c797195f64a1
Added to database: 07/06/2026, 23:02:29 UTC
Last enriched: 07/06/2026, 23:14:03 UTC
Last updated: 07/06/2026, 23:14:03 UTC
Views: 2
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