Vulnerability in org.springframework:spring-webflux (CVE-2026-41839)
Summary
Vulnerability in org.springframework:spring-webflux (CVE-2026-41839). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A WebFlux application with a compromised subdomain (for example, compromised via cross-site scripting (XSS)) is vulnerable to an escalation attack exchanging a known session ID for that of an authenticated user.
Affected versions:
Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-41839 has been found in org.springframework:spring-webflux.
Risk of unauthorized operations or information disclosure. CVSS score: 4.2/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "org.springframework:spring-webflux CVE-2026-41839" on the vendor's site.
CVE-2026-41839 (org.springframework:spring-webflux) — CWE-384 / CVSS v3 4.2
Attack vector: remote (network-reachable) / unauthenticated
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-384) exists in org.springframework:spring-webflux.
Check the vendor advisory for the affected versions of org.springframework:spring-webflux.
Severity: Medium (CVSS 4.2/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで org.springframework:spring-webflux を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-41839 libspring-java
- Ubuntu UBUNTU-CVE-2026-41839 libspring-java
References
- web spring.io
- web nvd.nist.gov
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com