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🟠 High | Source: Microsoft Security Response Center CVE-2026-5545 is a vulnerability involving the incorrect reuse of HTTP Negotiate authentication connections, which could allow an attacker to hijack or impersonate authenticated sessions. This type of flaw can lead to unauthorised access to resources by exploiting the way authentication tokens are shared across connections. It is particularly concerning in environments where multiple users or services share HTTP connections. Security Architect’s Take: Review any services or middleware that use HTTP Negotiate (Kerberos/NTLM) authentication and ensure connection pooling is configured to enforce strict session isolation. Apply the relevant Microsoft patches promptly and consider monitoring for anomalous authentication patterns that could indicate session hijacking. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-6429 is a credential leak vulnerability where netrc credentials can be inadvertently exposed when an HTTP proxy connection is reused across requests. This occurs because authentication credentials stored in netrc files may be transmitted to unintended destinations via a reused proxy connection. If exploited, an attacker with visibility into proxy traffic could capture sensitive credentials used by Azure-connected workloads. Security Architect’s Take: Review any Azure workloads or pipelines that use netrc files for credential storage alongside HTTP proxy configurations, and consider rotating any credentials that may have transited affected connections. Disable connection reuse on proxy clients where feasible, and audit proxy logs for unexpected credential forwarding until a patch is applied. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-4873 is a vulnerability in Azure where connection reuse logic fails to enforce TLS requirements, potentially allowing unencrypted connections to be used in place of secured ones. This could expose sensitive data in transit to interception or tampering. It matters because services relying on TLS for confidentiality and integrity may be silently bypassed without any visible error. Security Architect’s Take: Audit any Azure services or application configurations that rely on connection pooling or reuse, and ensure TLS enforcement is explicitly validated at the application layer rather than assumed. Consider enabling strict transport policies and monitoring for unexpected plaintext traffic in your network telemetry. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-6276 is a vulnerability in Azure where a stale custom cookie host configuration can cause session cookies to be leaked to unintended parties. This could allow an attacker to intercept or reuse authentication cookies, potentially gaining unauthorised access to user sessions or sensitive data. It matters because cookie leakage in cloud-hosted applications can lead to account takeover without requiring credentials. Security Architect’s Take: Review any Azure-hosted applications using custom cookie domain configurations and ensure cookie host settings are kept current and accurate — stale or misconfigured host entries should be audited and corrected promptly. Apply any available Microsoft patch and consider enforcing the Secure and SameSite=Strict cookie attributes as a defence-in-depth measure. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-6253 is a vulnerability in a Microsoft Azure-related component where proxy credentials can be inadvertently leaked when an HTTP redirect causes a request to be forwarded to a different proxy. An attacker who can influence redirect behaviour could potentially intercept or capture credentials used for proxy authentication, gaining unauthorised access to network resources or sensitive systems behind the proxy. Security Architect’s Take: Audit any Azure workloads or clients that authenticate to proxy servers — particularly those that follow HTTP redirects automatically — and apply Microsoft’s patch or workaround immediately. Consider enforcing proxy credential stripping on redirects at the network layer and reviewing proxy authentication logs for anomalous access patterns. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-34181 is a vulnerability in which PKCS#12 certificate files using the PBMAC1 MAC scheme are accepted even when configured with excessively short HMAC keys. Short HMAC keys weaken the integrity protection on PKCS#12 containers, potentially allowing an attacker to tamper with or forge certificate bundles without detection. This is particularly relevant to Azure services and applications that import or process PKCS#12 files for TLS certificates or authentication credentials. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-42764 is a NULL pointer dereference vulnerability in the QUIC protocol server’s handling of initial packets on Microsoft Azure. This type of flaw can typically be exploited by an unauthenticated remote attacker to crash the affected service, potentially causing a denial of service. It matters because QUIC is increasingly used for high-performance, low-latency connections, meaning internet-facing services relying on it could be disrupted without authentication. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-45447 is a heap use-after-free vulnerability in the PKCS7_verify() function, which is used to verify digitally signed data packages. This type of memory corruption flaw can potentially allow an attacker to execute arbitrary code or cause a crash by manipulating how memory is accessed after it has been freed. Given its presence in a cryptographic verification routine, it could undermine trust in signed content processed by affected Azure services or underlying components. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-45445 is a cryptographic vulnerability in OpenSSL’s AES-OCB mode where the Initialisation Vector (IV) is silently ignored when encryption or decryption is performed via the EVP_Cipher() API path. This means data intended to be protected with a unique IV may be encrypted with a predictable or reused nonce, undermining the confidentiality and integrity guarantees of AES-OCB. Any Azure service or workload relying on OpenSSL’s EVP_Cipher() with AES-OCB mode is potentially at risk of ciphertext forgery or plaintext recovery. ...

🟠 High | Source: Microsoft Security Response Center CVE-2026-47162 is a code injection vulnerability in Vim’s netrw plugin, specifically within the NetrwBookHistSave() function. A crafted directory name can trigger arbitrary Vimscript execution, potentially allowing an attacker to run malicious code in the context of the user running Vim. This is relevant to cloud environments where Vim is commonly used on Linux-based virtual machines and containers for editing configuration files. Security Architect’s Take: Audit your Linux VM and container base images to identify Vim versions in use and apply vendor patches promptly. Consider enforcing policy to restrict or replace Vim with minimal editors in production environments where netrw functionality is unnecessary, reducing the attack surface. ...