CVE-2026-40972: spring boot — Fix

Description

An attacker on the same network as the remote application may be able to utilize a timing attack to discover information about the remote secret. In extreme circumstances this could result in the attacker determining the secret and uploading changed classes, thereby achieving remote code execution in the remote application. Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); DevTools remote secret comparison. Versions that are no longer supported are also affected per vendor advisory.

Is your site exposed to CVE-2026-40972?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0004

Probability of exploitation

0.13%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-208 CWE-208

Affected Products

Vendor	Product	Versions
vmware	spring_boot	< 2.7.33
vmware	spring_boot	3.3.0 — 3.3.19
vmware	spring_boot	3.4.0 — 3.4.16
vmware	spring_boot	3.5.0 — 3.5.14
vmware	spring_boot	4.0.0 — 4.0.6

References

Advisories & Patches

https://spring.io/security/cve-2026-40972

Frequently Asked Questions

What is CVE-2026-40972? +

An attacker on the same network as the remote application may be able to utilize a timing attack to discover information about the remote secret. In extreme circumstances this could result in the attacker determining the secret and uploading changed classes, thereby achieving remote code execution in the remote application. Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); DevTools remote secret comparison. Versions that are no longer supported are also affected per vendor advisory. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-40972? +

CVE-2026-40972 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0004, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-40972? +

CVE-2026-40972 affects products from vmware, specifically: spring_boot. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40972? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-65630

Observable Timing Discrepancy vulnerability in potatosalad jose allows recovery of a long-term X25519 private key through a timing side channel …

CVE-2026-18036

In Bouncy Castle for Java before 1.86, NTRU reduced secret values with the % operator in three helpers whose reference …

CVE-2026-54736

Phalcon is a high-performance, full-stack PHP framework. Prior to 5.14.1, Phalcon\Encryption\Crypt::decrypt compares the attacker-supplied HMAC tag against the freshly computed …

CVE-2026-75589

Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify. Each of …

CVE-2026-78500

A blind server-side request forgery (SSRF) vulnerability WatchGuard Dimension Database Server Test configuration allows an authenticated privileged attacker to enumerate …

CVE-2026-8794

PaperCut NG/MF contains an observable timing discrepancy in its authentication component. An unauthenticated remote attacker can exploit this vulnerability to …