CVE-2026-65819 in gopacket
Summary
by MITRE • 08/07/2026
gopacket provides packet processing capabilities for Go. Through version 1.7.0, multiple layer decoders use attacker-controlled lengths, counts, or offsets before validating them against packet buffers, allowing a crafted packet decoded through DecodingLayerParser or DecodeFromBytes to trigger an unrecovered panic and remotely deny service. A patch commit is available at 210f25f.
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Analysis
by VulDB Data Team • 08/07/2026
The gopacket library serves as a fundamental packet processing toolkit for go applications, enabling developers to parse and analyze network traffic at various protocol layers. This vulnerability affects versions through 1.7.0 where multiple layer decoders within the library fail to properly validate attacker-controlled parameters before using them in packet buffer operations. The flaw specifically manifests in the DecodingLayerParser and DecodeFromBytes functions which process network packets without adequate bounds checking on lengths, counts, or offsets provided by external inputs.
The technical implementation of this vulnerability stems from insufficient input validation mechanisms within the packet parsing logic. When attackers craft malicious packets with carefully constructed length fields, count values, or offset parameters, these unvalidated inputs are directly used to index into packet buffers during decoding operations. This creates a condition where malformed packet data can cause out-of-bounds memory accesses or invalid pointer dereferences that result in program panics. The vulnerability operates at the intersection of CWE-129 Input Validation and CWE-787 Out-of-bounds Write, representing a classic buffer overflow scenario within network protocol parsing contexts.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enable more sophisticated attack vectors. Remote attackers can trigger unrecovered panics by sending specially crafted packets that cause the gopacket library to crash or terminate unexpectedly. This service disruption affects any application relying on gopacket for network traffic analysis, packet capture, or protocol inspection. The vulnerability is particularly concerning in network monitoring tools, intrusion detection systems, and any security infrastructure that depends on robust packet processing capabilities, as attackers could exploit this to render critical network services unavailable.
Mitigation strategies should focus on immediate patch application to version 1.7.1 or later where the fix commit 210f25f addresses the validation gaps in layer decoders. Organizations should also implement network ingress filtering and rate limiting to reduce exposure while patches are deployed. Additional defensive measures include runtime monitoring for unusual panic patterns and implementing proper error handling around packet parsing operations. The vulnerability demonstrates the importance of input validation in security-critical code paths and aligns with ATT&CK technique T1498 Lateral Tool Transfer, where attackers leverage library vulnerabilities to establish persistent access or maintain availability disruptions. Security teams should also consider implementing network segmentation to limit the attack surface where vulnerable applications reside, particularly in environments where packet processing is a core function of security infrastructure components.