Authentication Bypass in org.springframework.security:spring-security-web (CVE-2026-47838)
Summary
Authentication bypass in org.springframework.security:spring-security-web (CVE-2026-47838). Confidential information can be exposed externally. Exploitable via SubjectDnX509PrincipalExtractor.
Original description
The description as published by the source.
In Spring Security Web, SubjectDnX509PrincipalExtractor does not correctly handle certain malformed X.509 certificate CN values, which can lead to reading the wrong value for the username. In a carefully crafted certificate, this can lead to an attacker impersonating another user.
SubjectDnX509PrincipalExtractor is deprecated by this CVE and replaced with SubjectX500PrincipalExtractor. As part of updating, you should also migrate to SubjectX500PrincipalExtractor.
Affected versions:
Spring Security Enterprise 5.7.0 through 5.7.24; 5.8.0 through 5.8.26; 6.3.0 through 6.3.17; 6.4.0 through 6.4.17; 6.5.0 through 6.5.10.
OSS 6.5.0 through 6.5.10.
Source: GitHub Security Advisories (Global) 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-2026-47838 has been found in org.springframework.security:spring-security-web.
Attackers can target a specific entry point like SubjectDnX509PrincipalExtractor over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 6.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "org.springframework.security:spring-security-web CVE-2026-47838" on the vendor's site.
CVE-2026-47838 (org.springframework.security:spring-security-web) — CWE-287 / CVSS v3 6.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: SubjectDnX509PrincipalExtractor / SubjectX500PrincipalExtractor
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.
Authentication bypass (CWE-287) exists in org.springframework.security:spring-security-web. Attackers reach the vulnerable code path via SubjectDnX509PrincipalExtractor.
Check the vendor advisory for the affected versions of org.springframework.security:spring-security-web. Attack surface: SubjectDnX509PrincipalExtractor / SubjectX500PrincipalExtractor.
Severity: Medium (CVSS 6.8/10). Confidential information can be exposed externally.
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.security:spring-security-web 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
References
- advisory nvd.nist.gov
- advisory github.com
- package spring-projects/spring-security
- web spring.io
- web github.com