CVE-2026-69247
Description
A flaw was found in cryptography, a Python package for cryptographic primitives. This vulnerability, known as a Bleichenbacher oracle, arises during PKCS#7 EnvelopedData decryption. An attacker can exploit distinguishable error messages and timing differences during decryption to gain information about the content-encryption key. Exploitation requires a high-volume service, such as an S/MIME gateway, that automatically decrypts untrusted data matching a victim's certificate. Successful exploitation could lead to the disclosure of sensitive encryption keys, allowing an attacker to decrypt confidential communications.
Statement
Red Hat rates this Moderate (CVSS 3.1 5.9). Exploitation requires an application that decrypts attacker-supplied PKCS#7 EnvelopedData via pkcs7_decrypt_* and leaks errors or timing. GitHub CNA CVSS 4.0 8.2 assumes that oracle is readily available.
Mitigation
The vulnerable APIs were introduced in cryptography 44.0.0 and fixed in 50.0.0.
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 | 5.9 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality,Access Control
Technical Impact: Read Application Data; Bypass Protection Mechanism
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