CVE-2026-54783 is a high-severity security vulnerability in CoreWCF.Primitives (nuget), affecting versions < 1.8.1. It is fixed in 1.8.1, 1.9.1.
Impact The attacker, with one captured signed SOAP envelope from a victim and no other privileges, can invoke arbitrary operations on the service as the victim principal for the lifetime of the captured signing key. There is no rate limit on replays. The DetectReplays setting on transport-security bindings does not mitigate the issue because the attack does not reuse the original timestamp, the fresh timestamp in the wsse:Security header is what the replay-detection logic inspects. Patches Fixed in CoreWCF v1.8.1 and v1.9.1 Workarounds Ensure communication is protected by SSL/TLS to prevent capturing of signed SOAP envelope.
CVE-2026-54783 has a CVSS score of 7.4 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (1.8.1, 1.9.1). Upgrading removes the vulnerable code path.
nuget
CoreWCF.Primitives (< 1.8.1)CoreWCF.Primitives (>= 1.9.0, < 1.9.1)CoreWCF.Primitives → 1.8.1 (nuget)CoreWCF.Primitives → 1.9.1 (nuget)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-54783 is reachable in your applications. Explore open-source security for your team.
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Upgrade the following packages to resolve this vulnerability:
CoreWCF.Primitives to 1.8.1 or laterCoreWCF.Primitives to 1.9.1 or laterKodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-54783 is a high-severity security vulnerability in CoreWCF.Primitives (nuget), affecting versions < 1.8.1. It is fixed in 1.8.1, 1.9.1.
CVE-2026-54783 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
CoreWCF.Primitives (nuget) versions < 1.8.1 is affected.
Yes. CVE-2026-54783 is fixed in 1.8.1, 1.9.1. Upgrade to this version or later.
Whether CVE-2026-54783 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
CoreWCF.Primitives to 1.8.1 or laterCoreWCF.Primitives to 1.9.1 or later