CVE-2026-57226 in Suricata
Summary
by MITRE • 09/18/2026
Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.17 and 8.0.6, HTTP SWF decompression with the non-default swf-decompression feature and an unsafe decompress-depth can use the configured depth when allocating in src/util-file-decompression.c instead of limiting the allocation to the Flash file's actual data requirement. A crafted SWF response can therefore trigger an integer-related heap buffer overflow and crash Suricata; the default disabled feature and default depth are not affected. This issue is fixed in versions 8.0.6 and 7.0.17.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified involves a critical memory management flaw within the SWF decompression module of Suricata, specifically affecting network intrusion detection and prevention systems that have explicitly enabled the non-default swf-decompression feature with an unsafe decompress-depth configuration. This issue stems from improper input validation during the allocation phase for handling Shockwave Flash files. When processing HTTP responses containing SWF content, the system is designed to limit memory allocations based on the actual data requirements of the file structure rather than a potentially arbitrary configured depth parameter. However, in versions prior to 7.0.17 and 8.0.6, the implementation incorrectly utilizes the user-configured decompress-depth value for heap allocation sizing instead of calculating or enforcing limits based on the SWF file's actual structural constraints. This deviation from secure coding practices creates a scenario where an attacker can manipulate the input to trigger excessive memory requests that exceed intended boundaries.
From a technical perspective, this flaw constitutes an integer-related heap buffer overflow as classified under CWE-190 Integer Overflow or Wraparound and CWE-787 Out-of-bounds Write. The core issue lies in the failure to validate whether the decompression depth aligns with the physical size of the SWF payload before allocating memory resources. By relying on a configurable parameter that can be set arbitrarily high by an administrator, the system becomes susceptible to allocation errors when processing maliciously crafted SWF responses. An attacker who controls or influences the network traffic containing these crafted files can exploit this discrepancy to cause the application to write beyond the allocated buffer boundaries. This leads to memory corruption within the Suricata process space, which typically results in a denial of service condition characterized by an immediate crash of the detection engine. The vulnerability is strictly limited to configurations where swf-decompression is enabled and the decompress-depth is set to values that exceed safe operational limits; default installations with disabled features or standard depth settings remain unaffected.
The operational impact of this vulnerability centers on the availability of network security monitoring capabilities. Since Suricata serves as a primary line of defense for many organizations, detecting malicious traffic in real-time, its compromise directly undermines the integrity and reliability of the security infrastructure. A successful exploitation allows an adversary to disrupt continuous monitoring by causing service interruptions through process crashes. This denial-of-service effect can blind security operations centers to other concurrent attacks or create windows of opportunity for further intrusions that go undetected due to the downtime required to restart services. Furthermore, while the primary impact described is a crash, heap buffer overflows inherently carry risks beyond availability, including potential code execution if memory corruption patterns are carefully manipulated, although this specific report emphasizes the stability and denial-of-service aspects.
Mitigation strategies require immediate attention from system administrators managing Suricata deployments. The most effective remediation is to upgrade to version 7.0.17 or later for the stable branch or version 8.0.6 and above for the development branch, where the allocation logic has been corrected to properly limit memory usage based on actual file data requirements rather than configurable depth parameters. For environments that cannot immediately patch due to operational constraints, disabling the swf-decompression feature entirely is a viable workaround since it removes the attack vector associated with SWF processing. Additionally, if the feature must remain enabled for specific use cases, administrators should review and restrict the decompress-depth configuration to conservative values that align with expected legitimate traffic patterns, thereby reducing the risk of excessive allocation requests. Regular auditing of custom configurations against security best practices is essential to prevent similar misconfigurations in other modules.
This vulnerability maps to several entries within established cybersecurity frameworks. In terms of attack techniques, it relates to ATT&CK technique T1496 Resource Hijacking via denial-of-service conditions caused by application crashes. The underlying weakness aligns with CWE-787 Out-of-bounds Write and CWE-20 Improper Input Validation, highlighting the necessity for rigorous boundary checks in network processing engines. Understanding these classifications helps security teams contextualize the risk within broader threat landscapes and prioritize remediation efforts accordingly. By addressing this flaw through software updates or configuration hardening, organizations can maintain robust protection against threats targeting their intrusion detection infrastructure while ensuring high availability of critical monitoring services.