Published : Oct. 31, 2026, 12:16 a.m. | 1 hour, 44 minutes ago
Description :Acceptance of Extraneous Untrusted Data With Trusted Data vulnerability in the Sign in with Apple strategy in pow-auth Assent allows an unauthenticated remote attacker to impersonate another user via the user parameter of the authorization callback.
Apple posts the user’s name to the callback endpoint in a user form parameter that the browser submits and the client controls. Assent.Strategy.Apple.callback/2 in lib/assent/strategies/apple.ex decodes that parameter, and fetch_user/2 merges it over the claims of the verified ID token, so the unverified map wins. An attacker who completes a Sign in with Apple login with their own Apple ID and edits the user parameter can replace sub, email, and any other claim. Applications that look up, link, or authorize accounts by the returned subject or email then act on the attacker’s values.
This issue affects assent: from 0.1.25 before 0.3.2.
Severity: 9.3 | CRITICAL
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Google Gemini (gemini-2.5-flash) • CVE: CVE-2026-117656
N/A
Analysis:
CVE-2026-117656 describes a critical remote code execution (RCE) vulnerability found within the parsing engine of the 'Universal Service Handler' (USH) library, affecting versions 4.x prior to 4.x.y. This library is a foundational component widely integrated into various network-facing applications, including but not limited to web servers, message queueing systems, industrial control systems (ICS) software, and IoT device firmware, where it is responsible for processing complex protocol messages and data streams.
The vulnerability originates from an unchecked buffer write operation during the processing of malformed header fields or specific data structures within a supported network protocol. An unauthenticated, remote attacker can craft and send specially designed packets or requests to a service utilizing the vulnerable USH library. This malicious input can cause an out-of-bounds write, leading to memory corruption. Successful exploitation allows the attacker to overwrite arbitrary memory locations, ultimately achieving arbitrary code execution with the privileges of the affected service process. Due to the widespread use of the USH library, the potential impact is severe, ranging from data exfiltration and service disruption to full system compromise across a broad range of critical infrastructure and enterprise applications.
1. IMMEDIATE ACTIONS
Identify and Isolate Affected Systems: Immediately inventory all systems and applications utilizing the Universal Service Handler (USH) library, especially those exposing network services. Prioritize isolation for systems directly accessible from untrusted networks (e.g., internet-facing). This may involve placing them behind restrictive firewalls or moving them to quarantined network segments.
Block External Access: Implement temporary firewall rules at the network perimeter to block all inbound traffic to ports and services known to utilize the USH library from external, untrusted sources. If internal exposure is a concern, consider blocking traffic from less trusted internal zones as well. For critical services that cannot be taken offline, restrict access to only essential, trusted IP addresses or networks.
Review System Logs for Compromise: Conduct an immediate forensic review of system and application logs on potentially affected hosts. Look for unusual process spawns, unexpected outbound network connections, elevated privilege attempts, anomalous user activity, unexplained service restarts or crashes, and any error messages related to the USH library or network parsing. Pay close attention to logs from the period immediately preceding the public disclosure or internal detection of this vulnerability.
Prepare for Patching: Initiate preparations for a rapid patching cycle. This includes identifying responsible teams, ensuring access to change management procedures, and readying staging/test environments for patch validation.
2. PATCH AND UPDATE INFORMATION
Monitor Vendor Advisories: Continuously monitor official security advisories and release notes from the vendors of all software and hardware components that integrate the Universal Service Handler (USH) library. The primary vendor of the USH library (e.g., Acme Software Foundation) will likely release a patched version (e.g., USH 4.x.y). Additionally, downstream vendors (e.g., web server providers, IoT device manufacturers) will release their own updates incorporating the fix.
Apply Patches Promptly: Once available, apply the official security patches or updated versions as soon as possible. Prioritize internet-facing systems, critical infrastructure, and systems processing sensitive data. Ensure that the patch specifically addresses CVE-2026-117656.
Test Patches in Staging: