# CVE-2026-59276: Timing Attack via Non-Constant-Time Comparison of Sensitive Values

> Attackers can exploit timing differences in string comparisons to infer sensitive security values, potentially leading to information disclosure.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** CLEANSTART-2026-AA31447, CLEANSTART-2026-EV98830, CLEANSTART-2026-SI92815, ECHO-1d47-61cb-67e8, GHSA-vj7f-9q44-g5xv

## What is CVE-2026-59276?

CVE-2026-59276 is a medium-severity vulnerability in Spring Security, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Several components in Spring Security compare security-sensitive values using standard string equality (String.equals()) rather than a constant-time comparison. Because String.equals() returns as soon as it finds a differing character, the time taken to reject an incorrect value is proportional to the number of leading characters that match the expected value.
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-208 (Observable Timing Discrepancy)

## Which versions are affected by CVE-2026-59276?

It affects 1 product.


Products: Vmware Spring Security.

## How do I fix CVE-2026-59276?

Upgrade to a fixed version.

## Is CVE-2026-59276 being exploited?

There is no known exploitation of CVE-2026-59276 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-2026-59276 and fix it if it is affected.

What it is: CVE-2026-59276 is a medium-severity vulnerability in Spring Security, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-59276 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-2026-59276/ (Markdown: https://insights.sbomify.com/CVE-2026-59276/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59276
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59276
- OSV: https://osv.dev/vulnerability/CVE-2026-59276

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59276/
Summaries are generated and may contain mistakes; the official description above is the record.