GPUStack: Authentication bypass via trusted loopback source (reverse-proxy TCP peer or X-GPUStack-Real-IP header) grants unauthenticated…
GPUStack before 2.2.0 with force_auth_localhost at its default of false is exposed when a same-host reverse proxy connects over loopback. Fixed in 2.2.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.2.0
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure22/25Default setups, reachable over the network without a login
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity9.8/10CVSS 9.8
- No patch0/5No signal
What would change the score
- Would score about 72 if added to CISA KEV
- Would score about 67 if CISA's SSVC rates exploitation active
CVE-2026-102895 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.8 (critical) and affects gpustack; fixed in 2.2.0.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 32/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Default setups
- Fix
- Fixed in 2.2.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
GPUStack, an open-source GPU cluster manager for AI model serving, can be attacked remotely without logging in. By making requests appear to come from the local host, an attacker can change users and models, create persistent administrator API keys, read worker and cloud-provider secrets, and run code through the inference backend import endpoint.
Read the original description
GPUStack is an open-source GPU cluster manager for AI model serving and GPU instance provisioning. Prior to 2.2.0, get_current_user in gpustack/api/auth.py treated a loopback request source as the built-in administrator when force_auth_localhost was false, which was the default. A remote request could appear to originate from 127.0.0.1 because client_ip_getter accepted a same-host reverse proxy peer or a client-supplied X-GPUStack-Real-IP loopback value. The bypass allowed unauthenticated administrative access, including user and model changes, persistent administrator API-key creation, disclosure of worker and cloud-provider secrets, and code execution through POST /v2/inference-backends/from-yaml. Exploitation was observed in the wild against a 2.1.1 deployment. This issue is fixed in version 2.2.0.
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 2.2.0.
Workaround: Set force_auth_localhost=true to require authentication even for loopback requests.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- gpustack gpustack
fixed in 2.2.0
Evidence 4
- Advisory
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-102895
Is CVE-2026-102895 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
GPUStack trusts requests that arrive from a loopback address without requiring authentication, so a network client can gain full administrative access. The trust can come from a reverse proxy's loopback TCP connection or from a forged X-GPUStack-Real-IP header with a loopback value.Source: github.com
Which versions are affected by CVE-2026-102895?
gpustack: before 2.2.0.Source: cve.now feed data
Am I affected, and how do I check?
Versions before 2.2.0 are affected, and only when force_auth_localhost is false, which is the default. The version and the force_auth_localhost setting can be checked in the GPUStack configuration, and whether a same-host reverse proxy connects over loopback can be checked in its proxy_pass configuration.Source: github.com
How do I fix CVE-2026-102895?
Upgrade to GPUStack 2.2.0, which fixes the issue. Until the upgrade is done, set force_auth_localhost=true so that loopback requests also require authentication.Source: github.com