CVE-2023-48312: capsule-proxy is a reverse proxy for the capsule operator project

Q: How do I fix CVE-2023-48312?

capsule-proxy: upgrade to newer than 0.4.5. Exact commands for each OS are on this page.

Q: Is CVE-2023-48312 being exploited?

CVE-2023-48312 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-48312 affect?

CVE-2023-48312 affects capsule-proxy. Severity is critical (CVSS 9.8). capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All t

Q: How urgent is CVE-2023-48312?

Priority 56/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2023-48312 is a critical-severity flaw (CVSS 9.8) affecting capsule-proxy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All the clusters running with the `anonymous-auth` Kubernetes API Server setting disable (set to `false`) are affected since it would be possible to bypass the token review mechanism, interacting with the upper Kube

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-287
Published	2023-11-24
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: clastix

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-11-24 18:15 UTCPublished CVE record published
2026-06-17 06:33 UTCUpdated Record last modified

clastix capsule-proxy UPGRADE

Affected: <= 0.4.5

Fixed in: newer than 0.4.5

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy capsule-proxy || rpm -q capsule-proxy || capsule-proxy --version

2. UPGRADE to newer than 0.4.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade capsule-proxy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade capsule-proxy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-48312?

capsule-proxy: upgrade to newer than 0.4.5. Exact commands for each OS are on this page.

Is CVE-2023-48312 being exploited?

CVE-2023-48312 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-48312 affect?

CVE-2023-48312 affects capsule-proxy. Severity is critical (CVSS 9.8). capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All t

How urgent is CVE-2023-48312?

Priority 56/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Kubernetes vulnerabilities

Related CVEs

CVE-2023-46254 MEDIUM 4.3 UPGRADE UPGRADE capsule-proxy is a reverse proxy for Capsule kubernetes multi-tenancy framework

References

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