Vulnerability in Spring Security

CVE-2026-47842

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 null (all-zero) initialization vector. Spring Security 7.1.0 Spring Security 7.0.0 - 7.0.6 Spring Security 6.5.0 - 6.5.11 Spring Security 6.4.0 - 6.4.18 Spring Security 5.8.0 - 5.8.27 Spring Security 5.7.0 - 5.7.25

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (3.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-47842: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-47842?
CVE-2026-47842 is a medium-severity vulnerability in Spring Security, classified under Inadequate Encryption Strength. CVSS score: 6.5/10. Published 2026-08-26.
How severe is CVE-2026-47842?
Medium severity. CVSS v3 base score is 6.5 out of 10.