How severe is CVE-2025-23028?

CVE-2025-23028 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2025-23028?

CVE-2025-23028 affects the following packages: github.com/cilium/cilium (Go), github.com/cilium/cilium (Go), github.com/cilium/cilium (Go). Ecosystems affected: Go.

How do I fix CVE-2025-23028?

Update github.com/cilium/cilium to 1.14.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-23028 is resolved across your whole dependency graph.

How do I detect CVE-2025-23028 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-23028 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2025-23028 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-23028 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-23028?

CVE-2025-23028 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-23028?

CVE-2025-23028 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-23028 published, and has it been updated?

CVE-2025-23028 was published on January 22, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

MEDIUM severity

CVE-2025-23028 — cilium

MEDIUMFix: cilium/cilium#36252

CVE-2025-23028 is a medium-severity (CVSS 5.3) CWE-770 vulnerability in github.com/cilium/cilium. A fix is available for github.com/cilium/cilium — see the affected versions and patch details below.

DoS in Cilium agent DNS proxy from crafted DNS responses

Also known asBIT-cilium-2025-23028BIT-cilium-operator-2025-23028BIT-hubble-relay-2025-23028GHSA-9m5p-c77c-f9j7GO-2025-3415

Published

Jan 22, 2025

Updated

Oct 28, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-23028.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

3 pkgs affected

🐹github.com/cilium/cilium🐹github.com/cilium/cilium🐹github.com/cilium/cilium

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

In a Kubernetes cluster where Cilium is configured to proxy DNS traffic, an attacker can crash Cilium agents by sending a crafted DNS response to workloads from outside the cluster.

For traffic that is allowed but without using DNS-based policy, the dataplane will continue to pass traffic as configured at the time of the DoS. For workloads that have DNS-based policy configured, existing connections may continue to operate, and new connections made without relying on DNS resolution may continue to be established, but new connections which rely on DNS resolution may be disrupted. Any configuration changes that affect the impacted agent may not be applied until the agent is able to restart.

Patches

This issue affects:

Cilium v1.14 between v1.14.0 and v1.14.17 inclusive
Cilium v1.15 between v1.15.0 and v1.15.11 inclusive
Cilium v1.16 between v1.16.0 and v1.16.4 inclusive

This issue is fixed in:

Cilium v1.14.18
Cilium v1.15.12
Cilium v1.16.5

Workarounds

There are no known workarounds to this issue.

Acknowledgements

The Cilium community has worked together with members of Isovalent and the Cisco Advanced Security Initiatives Group (ASIG) to prepare these mitigations. Special thanks to @kokelley-cisco for reporting this issue and @bimmlerd for the fix.

For more information

If you have any questions or comments about this advisory, please reach out on Slack.

If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [email protected]. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/cilium/cilium`	≥ 1.14.0&&< 1.14.18	1.14.18`go get github.com/cilium/cilium@v1.14.18`
🐹Go	`github.com/cilium/cilium`	≥ 1.15.0&&< 1.15.12	1.15.12`go get github.com/cilium/cilium@v1.15.12`
🐹Go	`github.com/cilium/cilium`	≥ 1.16.0&&< 1.16.5	1.16.5`go get github.com/cilium/cilium@v1.16.5`

Affected Products

1 product · 3 configurations

Application

ciliumcilium

≥ 1.16.0 && < 1.16.5

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/cilium/cilium to 1.14.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-23028 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### Impact In a Kubernetes cluster where Cilium is configured to proxy DNS traffic, an attacker can crash Cilium agents by sending a crafted DNS response to workloads from outside the cluster. For traffic that is allowed but without using DNS-based policy, the dataplane will continue to pass traffic as configured at the time of the DoS. For workloads that have DNS-based policy configured, existing connections may continue to operate, and new connections made without relying on DNS resolution may continue to be established, but new connections which rely on DNS resolution may be disrupted. An