CVE-2026-48758
Description
A flaw was found in the @sigstore/core component. The preAuthEncoding function incorrectly uses Node.js 'ascii' encoding when converting Pre-Authentication Encoding (PAE) strings to bytes. This encoding truncates Unicode characters to their low byte, allowing an attacker to substitute characters in the payloadType with Unicode variants that produce identical PAE bytes. As a result, the payloadType can be mutated after a digital signature has been applied without invalidating the signature, thereby bypassing the intended type-binding guarantee of the Digital Signature Standard for Entity Authentication (DSSE).
Statement
A flaw was found in @sigstore/core. The preAuthEncoding function uses Node.js ASCII encoding which truncates Unicode characters to their low byte, allowing payloadType to be mutated after signing without invalidating the DSSE signature.
Mitigation
Upgrade to @sigstore/core 3.2.1 or later.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.4 | N/A | 5.4 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
Understanding the Weakness (CWE)
Access Control,Integrity,Confidentiality
Technical Impact: Gain Privileges or Assume Identity; Modify Application Data; Execute Unauthorized Code or Commands
An attacker could gain access to sensitive data and possibly execute unauthorized code.
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