What is the CVSS score of CVE-2026-48815?

CVE-2026-48815 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. EPSS exploitation probability: 0.2%.

Is there a public PoC exploit available for CVE-2026-48815?

Yes, a public proof-of-concept exploit is available for CVE-2026-48815. Prioritise patching immediately. EPSS: 0.2%.

Is there a patch available for CVE-2026-48815?

Yes, a patch is available for CVE-2026-48815. Update the affected software to the latest version immediately.

sigstore-js CVE-2026-48815

EUVD-2026-44494 HIGH

Improper Verification of Cryptographic Signature (CWE-347)

2026-07-01 https://github.com/sigstore/sigstore-js

GHSA-52v5-jr5w-gjxr

Authentication Bypass Jwt Attack

7.5

CVSS 3.1 · Vendor: https://github.com/sigstore/sigstore-js

Severity by source

Vendor (https://github.com/sigstore/sigstore-js) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

vuln.today AI

5.9 MEDIUM

Integrity-only bypass (I:H, C/A:N); AC:H because it requires the non-default certificateOIDs config plus a certificate that still passes the enforced SAN/issuer checks; no privileges or interaction needed.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (https://github.com/sigstore/sigstore-js).

CVSS VectorVendor: https://github.com/sigstore/sigstore-js

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Lifecycle Timeline

CVE Published

Jul 01, 2026 - 20:19 cve.org

HIGH 7.5

Analysis Generated

Jul 01, 2026 - 20:17 vuln.today

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

3,403 npm packages depend on sigstore (89 direct, 3,315 indirect)

Ecosystem-wide dependent count for version 4.1.1.

DescriptionCVE.org

Summary

The documented certificateOIDs option in sigstore.verify() is accepted by the public API but discarded before verification, so required certificate extension OIDs are never checked.

Details

The public verify options include certificateOIDs and the documentation says those OID/value pairs “must be present in the certificate’s extension list.” The policy-construction path used by sigstore.verify() and createVerifier() only copies the SAN and issuer settings into the verification policy and completely ignores certificateOIDs.

As a result, callers can believe they are constraining verification to certificates carrying specific Fulcio or workload-identifying OIDs, while the actual verifier never receives those constraints. Any bundle that satisfies the remaining checks is accepted even if the required OID extensions are absent or mismatched.

This is reachable from supported usage through the documented certificateOIDs verify option.

PoC

javascript

const { createVerificationPolicy } = require("sigstore/dist/config");

const policy = createVerificationPolicy({
  certificateIssuer: "https://issuer.example",
  certificateIdentityEmail: "victim@example.com",
  certificateOIDs: {
    "1.2.3.4": "required-value",
  },
});

console.log("certificateOIDs" in policy, JSON.stringify(policy));
// false {"subjectAlternativeName":"victim@example.com","extensions":{"issuer":"https://issuer.example"}}

Impact

Applications that rely on certificateOIDs to restrict which certificates may sign artifacts receive no such protection. Unauthorized certificates that should be rejected on extension policy can be accepted as long as they satisfy the remaining verification checks.

AnalysisAI

Signature verification policy bypass in the sigstore npm package allows attackers to have unauthorized signing certificates accepted despite explicit OID-based restrictions. The documented certificateOIDs verify option - used by sigstore.verify() and createVerifier() to require specific Fulcio/workload-identity extension OIDs - is silently discarded during policy construction, so those extension constraints are never enforced while callers believe they are. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access

Obtain certificate passing SAN/issuer checks

Delivery

Craft signed bundle lacking required OIDs

Exploit

Submit bundle to app using certificateOIDs

Execution

certificateOIDs constraint silently skipped

Impact

Unauthorized artifact accepted as trusted

Access

Obtain certificate passing SAN/issuer checks

Delivery

Craft signed bundle lacking required OIDs

Exploit

Submit bundle to app using certificateOIDs

Execution

certificateOIDs constraint silently skipped

Impact

Unauthorized artifact accepted as trusted

Vulnerability AssessmentAI

Exploitation	Exploitation requires that the target application invokes `sigstore.verify()` or `createVerifier()`/`createVerificationPolicy()` with the `certificateOIDs` option set and treats those OID/value pairs as a security-relevant restriction - this is a non-default, opt-in usage, not the library baseline. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	The CVSS 3.1 base score is 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N), reflecting an integrity-only impact with no confidentiality or availability loss - consistent with a verification bypass rather than code execution or data disclosure. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An organization verifies signed artifacts with `sigstore.verify()` and passes `certificateOIDs` to require a workload-identity extension that only its trusted build system's Fulcio certificates carry. Because that constraint is silently discarded, an attacker who obtains any certificate matching the configured issuer and identity - but lacking the required OID - can produce a bundle that passes verification, and the application accepts a malicious artifact it should have rejected. …
Remediation	Upgrade to the fixed release of the sigstore npm package as directed by advisory GHSA-52v5-jr5w-gjxr (https://github.com/sigstore/sigstore-js/security/advisories/GHSA-52v5-jr5w-gjxr); the exact patched version is not present in the provided data and should be taken from the advisory. … Detailed patch versions, workarounds, and compensating controls in full report.