CVE-2026-58161 in Traffic Server
Summary
by MITRE • 07/29/2026
Apache Traffic Server can crash from null dereferences and dangling references in TLS and SNI handling.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3.
Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
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Analysis
by VulDB Data Team • 07/29/2026
The vulnerability in Apache Traffic Server represents a critical security flaw that manifests through null dereferences and dangling references during TLS and SNI (Server Name Indication) processing within the HTTP proxy server. This issue affects multiple version ranges including 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3, indicating a widespread problem that has persisted across several major releases of the software. The root cause lies in improper memory management during SSL/TLS connection handling where the application fails to properly validate pointer references before dereferencing them, creating opportunities for denial of service conditions and potential exploitation.
The technical implementation of this vulnerability stems from insufficient input validation and memory safety checks within the TLS handshake process, particularly when processing SNI extensions that clients send to specify which certificate they intend to use for communication. When malformed or unexpected SNI data is received, the server's handling code can attempt to access null pointers or references to freed memory locations, leading to segmentation faults and subsequent application crashes. This behavior aligns with CWE-476 which specifically addresses null pointer dereference vulnerabilities, and represents a classic example of improper handling of dynamic memory allocation in network protocol implementations.
The operational impact of this vulnerability extends beyond simple service disruption as it can be exploited by remote attackers to perform denial of service attacks against Apache Traffic Server instances. Attackers can craft malicious TLS handshakes with specially crafted SNI values that trigger the null dereference conditions, causing the proxy server to terminate unexpectedly and potentially leaving legitimate users unable to access services. This vulnerability particularly affects web applications that rely on Apache Traffic Server as a reverse proxy or content accelerator, where service availability is critical for business operations. The issue demonstrates how seemingly minor memory management flaws can have significant operational consequences in high-availability systems.
Organizations utilizing affected versions of Apache Traffic Server should immediately implement the recommended upgrades to version 9.2.15 or 10.1.4 which contain the necessary patches to address the null dereference and dangling reference conditions in TLS and SNI handling. The fix likely involves implementing proper pointer validation checks before memory access operations, ensuring that all SNI data is properly validated and sanitized before processing, and maintaining appropriate memory lifecycle management during SSL/TLS connection establishment. Security teams should also consider implementing network-level monitoring to detect unusual TLS handshake patterns that might indicate exploitation attempts, while the mitigation strategy should include comprehensive testing of the patched versions in staging environments before production deployment. This vulnerability exemplifies the importance of robust memory safety practices in network infrastructure software and aligns with ATT&CK technique T1499.002 which covers resource exhaustion attacks through service interruption, demonstrating how improper error handling can create exploitable conditions that adversaries can leverage for system compromise or availability disruption.