Vulnerability in CoreWCF.Primitives (CVE-2026-54773)
Summary
Vulnerability in CoreWCF.Primitives (CVE-2026-54773). Data can be tampered with by attackers. Exploitable via KeyInfo. Mitigation: upgrade to 1.9.1 or later.
Original description
The description as published by the source.
Impact
An unauthenticated remote attacker who can place a SOAP header lexically before wsse:Security can embed a ds:Signature of their choosing inside that header and cause the server to verify the attacker-supplied signature instead of the one carried in the security header.
Preconditions
Exploitation requires the endpoint be configured with an endorsing supporting token binding, and the attacker constructs a ds:Signature whose KeyInfo resolves through the receive-side token resolver to a key under the attacker’s control. Both are conditions outside the attacker’s direct control on a generic deployment.
Patches
Fixed in CoreWCF v1.8.1 and v1.9.1
Workarounds
Use a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates).
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-2026-54773 has been found in CoreWCF.Primitives.
Attackers can target a specific entry point like KeyInfo over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 5.9/10.
What to do: upgrade CoreWCF.Primitives to 1.9.1 or later.
If unsure, ask your IT team or search "CoreWCF.Primitives CVE-2026-54773" on the vendor's site.
CVE-2026-54773 (CoreWCF.Primitives) — CWE-347 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: KeyInfo
Patched: 1.9.1 — apply immediately
Workaround: Use a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates).
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-347) exists in CoreWCF.Primitives. Attackers reach the vulnerable code path via KeyInfo without authentication.
Check the vendor advisory for the affected versions of CoreWCF.Primitives. Attack surface: KeyInfo.
Severity: Medium (CVSS 5.9/10). Data can be tampered with by attackers.
Update to 1.9.1.
Workaround: Use a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates).
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'CoreWCF.Primitives' . against your dependency files (package-lock.json, requirements.txt, go.sum) 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
grep -r 'CoreWCF.Primitives' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
CoreWCF.Primitivesを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Use a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates).パッチが適用されるまでの応急処置として、Use a security token resolver that only accepts references to issuer-pinned X.509 chains (the default when expecting a static set of signing certificates). を実施。回避策の副作用 (機能低下) を確認した上で。
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3Apply patch patch
Upgrade CoreWCF.Primitives to 1.9.1ステージング環境で 1.9.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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4Post-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。