CVE-2026-47842
Description
A flaw was found in Spring Security. Applications configured to use AesBytesEncryptor with a two-argument constructor or a null Initialization Vector (IV) generator in Cipher Block Chaining (CBC) mode will encrypt data using a predictable, all-zero IV. This deterministic encryption allows an attacker to analyze encrypted data and potentially deduce patterns, leading to the disclosure of sensitive information.
Statement
A flaw was found in Spring Security. Applications using AesBytesEncryptor with the two-argument constructor or when passing a null IV generator and CBC as the encryption mode encrypt data with AES/CBC using a fixed all-zero initialization vector. Because the IV is deterministic, identical plaintexts always produce identical ciphertext for a given password and salt. An attacker with read access to the encrypted data store can exploit this to determine when two records share the same plaintext value, correlate encrypted values across rows or users, and mount dictionary attacks by pre-encrypting candidate values and comparing results. This is a continuation of CVE-2020-5408.
Mitigation
Upgrade to a fixed version of Spring Security (7.1.1, 7.0.7, 6.5.12, 6.4.19, 5.8.28, or 5.7.26). Alternatively, migrate from the deprecated AesBytesEncryptor to the new AesCbcBytesEncryptor or AesGcmBytesEncryptor classes which use secure random IV generation. If using Encryptors.standard(), Encryptors.stronger(), Encryptors.text(), or Encryptors.delux(), these are also deprecated and should be replaced. Review the Spring Security migration guide to determine whether data re-encryption is required.
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 | 6.5 | N/A | 6.5 |
| 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 | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
If the IV is not properly initialized, data that is encrypted can be compromised and information about the data can be leaked. See [REF-1179].
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