CVE-2026-48815
ADVISORY - githubSummary
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
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.
Common Weakness Enumeration (CWE)
Improper Verification of Cryptographic Signature
GitHub
3.9
CVSS SCORE
7.5high| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| sigstore | npm | - | - | <=4.1.0 | 4.1.1 |
CVSS:3 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery (IPv6) flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.
The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
The vulnerable system can be exploited without interaction from any user.
An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
There is no loss of confidentiality.
There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any or all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
There is no impact to availability within the impacted component.
minimos
MINI-3ffx-ppx9-53qm
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