CVE-2026-58179 in Traffic Server
Summary
by MITRE • 07/29/2026
The Apache Traffic Server regex_remap plugin overflows the stack and integers from substitution input.
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 Apache Traffic Server regex_remap plugin contains a critical vulnerability that manifests as stack buffer overflow and integer overflow conditions when processing substitution input within regular expression patterns. This flaw exists in multiple version ranges spanning from 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3, making it a widespread issue affecting the core traffic management functionality of the server. The vulnerability stems from insufficient input validation and boundary checking within the plugin's handling of regex substitution operations where user-provided data is directly incorporated into buffer operations without proper sanitization.
The technical implementation flaw occurs when the plugin processes regular expression patterns that include substitution components such as \1, \2, or similar backreferences in the replacement string. When maliciously crafted input containing excessive length sequences or malformed numeric values is passed through these substitution mechanisms, the system fails to properly validate the input boundaries before performing memory operations. This results in stack memory corruption through buffer overflow conditions and integer overflows that can lead to arbitrary code execution or denial of service scenarios. The vulnerability maps directly to CWE-121 Stack-based Buffer Overflow and CWE-190 Integer Overflow or Wraparound, both of which are classified as high-risk security issues under the Common Weakness Enumeration framework.
The operational impact of this vulnerability extends beyond simple service disruption as it presents a significant attack surface for adversaries seeking to compromise Apache Traffic Server deployments. An attacker could potentially exploit this through carefully crafted HTTP requests containing maliciously formatted regular expression patterns in the remap configuration files or through direct input manipulation in proxy configurations. The vulnerability allows for both remote code execution and denial of service conditions, making it particularly dangerous in production environments where traffic servers handle critical network traffic routing. Attackers could leverage this weakness to execute arbitrary commands on the server, escalate privileges, or cause persistent service outages that would affect all traffic passing through the compromised server instance.
Mitigation strategies for this vulnerability include immediate upgrading to the patched versions 9.2.15 or 10.1.4, which contain proper input validation and boundary checking mechanisms. Organizations should also implement additional defensive measures such as restricting access to regex_remap plugin configurations, monitoring for anomalous patterns in traffic logs that might indicate exploitation attempts, and implementing network segmentation to limit potential attack vectors. The fix addresses the root cause by ensuring proper bounds checking on substitution input and implementing robust integer overflow protection mechanisms. Security teams should also consider applying runtime protections such as stack canaries, address space layout randomization, and control flow integrity checks as additional layers of defense against similar vulnerabilities that may exist in other components of the traffic server ecosystem. This vulnerability demonstrates the importance of validating all user-supplied input in network infrastructure components and aligns with ATT&CK technique T1059.007 for command and scripting interpreter to understand how such flaws can be exploited for code execution within proxy server environments.