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HIGH severity

CVE-2026-40973 — spring-boot

HIGH

CVE-2026-40973 is a high-severity (CVSS 7) CWE-377 vulnerability in org.springframework.boot:spring-boot. A fix is available for org.springframework.boot:spring-boot — see the affected versions and patch details below.

Spring Boot accepts predictable temp directory without ownership verification

Also known asGHSA-wwpq-f5c3-7hvx
Published
Updated
Affected
5 pkgs
Patched
2 / 5
Exploits
None indexed
Exploitation data as of Nov 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40973.

EPSS Exploitation Probability

via FIRST.org ↗
0.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs3th percentile — riskier than 3% of all scored CVEsHighest risk
0.00%0.21%0.42%0.64%0.0%0.1%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

5 pkgs affected
☕org.springframework.boot:spring-boot☕org.springframework.boot:spring-boot☕org.springframework.boot:spring-boot☕org.springframework.boot:spring-boot☕org.springframework.boot:spring-boot

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

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 Packages

5 total 2 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenorg.springframework.boot:spring-boot≥ 4.0.0&&< 4.0.64.0.6org.springframework.boot:spring-boot:4.0.6
☕Mavenorg.springframework.boot:spring-boot≥ 3.5.0&&< 3.5.143.5.14org.springframework.boot:spring-boot:3.5.14
☕Mavenorg.springframework.boot:spring-boot≥ 3.4.0No fix
☕Mavenorg.springframework.boot:spring-boot≥ 3.3.0No fix
☕Mavenorg.springframework.boot:spring-bootall versionsNo fix

Affected Products

1 product · 5 configurations
Application
spring bootvmware
≥ 4.0.0 && < 4.0.6
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.springframework.boot:spring-boot, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update org.springframework.boot:spring-boot to 4.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40973 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate
Workaround published by Red Hat
To mitigate this issue, ensure that the `server.servlet.session.persistent` property is set to `false` in your Spring Boot application's configuration. This prevents session information from being written to the predictable temporary directory, thereby removing the conditions necessary for exploitation. Disabling persistent sessions may affect application behavior that relies on session data surviving restarts.
Source: Red Hat security advisory for CVE-2026-40973 (CC BY 4.0)
ProductFixed inAdvisory
HawtIO HawtIO 4.4.0spring-bootRHSA-2026:25089
Red Hat build of Apache Camel 4.18.1 for Spring Boot 3.5.14spring-bootRHSA-2026:17668
Red Hat OpenShift Dev Spaces 3.28devspaces/openvsx-rhel9:1779528224RHSA-2026:21772

Frequently Asked Questions

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` owner
O3 Security · Impact-Aware SCA

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CVE-2026-40973: spring-boot — Fixed in 4.0.6