# CVE-2026-47842: Deterministic AES/CBC Encryption in Spring Security AesBytesEncryptor Allows Ciphertext Correlation

> Attackers can correlate ciphertexts due to deterministic AES/CBC encryption with null IVs in Spring Security, requiring specific constructor usage or null IV generators.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Aug 2026
- **Updated:** 26 Aug 2026
- **Also known as:** CLEANSTART-2026-DN56273, CLEANSTART-2026-OS01121, CLEANSTART-2026-QY38876, ECHO-b053-d09f-b66c, GHSA-7274-w8xr-fr2w

## What is CVE-2026-47842?

CVE-2026-47842 is a medium-severity vulnerability in Spring Security, published on 26 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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

Weakness: CWE-326 (Inadequate Encryption Strength)

## Which versions are affected by CVE-2026-47842?

It affects 1 product.


Products: Vmware Spring Security.

## How do I fix CVE-2026-47842?

Upgrade to a fixed version.

## Is CVE-2026-47842 being exploited?

There is no known exploitation of CVE-2026-47842 in the wild and no public exploit code.

## Other vulnerabilities in Spring Security

- [CVE-2014-3527](https://insights.sbomify.com/CVE-2014-3527/): Authorization Bypass in Spring Security (critical 9.8)
- [CVE-2026-59354](https://insights.sbomify.com/CVE-2026-59354/): Spring Security OAuth2 Authorization Server: Insufficient validation of Dynamic Client Registration metadata (critical 9.6)
- [CVE-2026-59270](https://insights.sbomify.com/CVE-2026-59270/): Spring Security embedded UnboundID LDAP server exposes well-known administrative bind DN on all network interfaces (critical 9.4)
- [CVE-2026-22732](https://insights.sbomify.com/CVE-2026-22732/): Under Some Conditions Spring Security HTTP Headers Are not Written (critical 9.1)
- [CVE-2023-34034](https://insights.sbomify.com/CVE-2023-34034/): Access Control Bypass in Spring Security (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47842 and fix it if it is affected.

What it is: CVE-2026-47842 is a medium-severity vulnerability in Spring Security, published on 26 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-47842 in the wild and no public exploit code.

Affected product: Spring Security. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47842/ (Markdown: https://insights.sbomify.com/CVE-2026-47842/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47842
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47842
- OSV: https://osv.dev/vulnerability/CVE-2026-47842

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47842/
Summaries are generated and may contain mistakes; the official description above is the record.