CVE-2026-40973

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-27 · updated 2026-07-24
Weakness: CWE-377

Description

A local attacker on the same host as the application may be able to take control of the directory used by `ApplicationTemp`. When `server.servlet.session.persistent` is set to `true` and the attack persists across application restarts, this may allow the attacker to read session information and hijack authenticated users or deploy a gadget chain and execute code as the application's user. 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); predictable temp directory / `ApplicationTemp` ownership verification. Versions that are no longer supported are also affected per vendor advisory.

Affected products

Spring Boot: before 2.7.33; from 3.3.0 before 3.3.19; from 3.4.0 before 3.4.16; from 3.5.0 before 3.5.14; from 4.0.0 before 4.0.6 — fixed in 2.7.33, 3.3.19, 3.4.16, 3.5.14, 4.0.6
Spring Boot: from 4.0.0 before 4.0.6; from 3.5.0 before 3.5.14; from 3.4.0 before 3.4.16; from 3.3.0 before 3.3.19; from 2.7.0 before 2.7.33 — fixed in 4.0.6, 3.5.14, 3.4.16, 3.3.19, 2.7.33

How to fix

Upgrade to a fixed version: Spring Boot 2.7.33, 3.3.19, 3.4.16, 3.5.14; Spring Boot 4.0.6, 3.5.14, 3.4.16, 3.3.19. Check the vendor advisory for mitigations.

References

https://spring.io/security/cve-2026-40973

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