How severe is CVE-2026-54457?

CVE-2026-54457 has a CVSS score of 7.7/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-54457?

CVE-2026-54457 affects the following packages: tensorzero (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-54457?

Update tensorzero to 2026.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54457 is resolved across your whole dependency graph.

How do I detect CVE-2026-54457 in my PyPI dependencies?

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

How do I mitigate CVE-2026-54457 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2026-54457 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-54457 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-2026-54457?

CVE-2026-54457 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 33th 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-2026-54457?

CVE-2026-54457 is classified as CWE-552 (CWE-552), Server-Side Request Forgery (SSRF) (CWE-918). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-54457 published, and has it been updated?

CVE-2026-54457 was published on August 21, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

HIGH severity

CVE-2026-54457 — tensorzero

HIGHFix: tensorzero/tensorzero@0abbc83

CVE-2026-54457 is a high-severity (CVSS 7.7) CWE-552 vulnerability in tensorzero. A fix is available for tensorzero — see the affected versions and patch details below.

TensorZero: Arbitrary file read and SSRF in TensorZero Gateway's internal object storage endpoint

Also known asGHSA-824w-x939-6cmcPYSEC-2026-3541

Published

Aug 21, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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-2026-54457.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2026-54457 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍tensorzero

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

Description

Impact

The /internal/object_storage endpoint accepts a caller-supplied JSON storage_path parameter that dynamically overrides the TensorZero [object_storage] configuration.

By abusing the filesystem storage type, a caller can read arbitrary files from the gateway filesystem, including files that may contain sensitive credentials. Similarly, by abusing the s3_compatible storage type, the caller can coerce the gateway into making outbound object storage requests to attacker-chosen internal/cloud-metadata endpoints.

This vulnerability only applies when the gateway can be accessed by untrusted callers. If a developer's TensorZero deployment has authentication enabled, only authenticated callers can exploit this vulnerability. If a developer's deployment has authentication disabled, any caller can exploit this vulnerability.

Remediation

The vulnerability has been patched in version 2026.6.0. See PR #7527.

Workarounds

If developers are unable to upgrade a gateway that is exposed to untrusted callers, please block external access to the /internal/object_storage endpoint.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`tensorzero`	all versions	2026.6.0`pip install --upgrade 'tensorzero==2026.6.0'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tensorzero, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tensorzero to 2026.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54457 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

### Impact The `/internal/object_storage` endpoint accepts a caller-supplied JSON `storage_path` parameter that dynamically overrides the TensorZero `[object_storage]` configuration. By abusing the `filesystem` storage type, a caller can read arbitrary files from the gateway filesystem, including files that may contain sensitive credentials. Similarly, by abusing the `s3_compatible` storage type, the caller can coerce the gateway into making outbound object storage requests to attacker-chosen internal/cloud-metadata endpoints. This vulnerability only applies when the gateway can be accessed