CVE-2026-4177
YAML::Syck versions through 1.
Executive Summary
CVE-2026-4177 is a critical severity vulnerability affecting binary-analysis, ai-code. It is classified as Heap-based Buffer Overflow. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"This critical flaw stems from within YAML::Syck versions, allowing an architectural oversight in input validation. In practice, this allows unauthorized actors to inject malicious logic that alters the execution flow of the application engine. Precogs Binary SAST/DAST engine uncovers boundary violations in compiled software to prevent unauthorized logical exploitation."
What is this vulnerability?
CVE-2026-4177 is categorized as a critical Buffer Overflow flaw. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter...
This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.
Risk Assessment
| Metric | Value |
|---|---|
| CVSS Base Score | 9.1 (CRITICAL) |
| Vector String | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| Published | March 16, 2026 |
| Last Modified | March 17, 2026 |
| Related CWEs | CWE-122 |
Impact on Systems
✅ Remote Code Execution: Attackers can overwrite the instruction pointer (EIP/RIP) to redirect execution to malicious shellcode.
✅ Memory Corruption: Overwriting adjacent memory regions can corrupt critical application state, leading to unpredictable privilege escalation.
✅ Denial of Service: Triggering segmentation faults and kernel panics results in immediate disruption of critical systems.
How to fix this issue?
Implement the following strategic mitigations immediately to eliminate the attack surface.
1. Memory-Safe Languages Where possible, migrate critical parsing logic to memory-safe languages like Rust or Go.
2. Safe Standard Libraries Replace unbounded C functions (strcpy, sprintf) with boundary-checking equivalents (strncpy, snprintf).
3. Compiler Defenses Ensure software is compiled with modern defensive flags: ASLR, DEP/NX, Stack Canaries (SSP), and Position Independent Executables (PIE).
Vulnerability Signature
// Vulnerable C Function
void parse_network_packet(char *untrusted_data) \{
char local_buffer[128];
// VULNERABLE: strcpy does not verify the length of the source data
strcpy(local_buffer, untrusted_data);
printf("Packet Processed.");
\}
// EXPLOIT PAYLOAD: 128 bytes of padding + [Overwrite EIP Address]
References and Sources
- NVD — CVE-2026-4177
- MITRE — CVE-2026-4177
- CWE-122 — MITRE CWE
- CWE-122 Details
- Binary Analysis Vulnerabilities
- AI Code Security Vulnerabilities
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | Network packet or file input |
| Vector | Data exceeds the allocated buffer bounds during a copy operation on the heap |
| Sink | strcpy(), memcpy(), or pointer arithmetic |
| Impact | Memory corruption, Remote Code Execution (RCE) |
Vulnerable Code Pattern
// ❌ VULNERABLE: Heap-based Buffer Overflow
void process_data(char *input) {
char *buffer = malloc(64);
// Taint sink: copies without bounds checking
strcpy(buffer, input);
}
Secure Code Pattern
// ✅ SECURE: Bounded copy
void process_data(char *input) {
char *buffer = malloc(64);
if (buffer != NULL) {
// Sanitized boundary check
strncpy(buffer, input, 63);
buffer[63] = '\0';
}
}
How Precogs Detects This
Precogs Binary SAST engine explicitly uncovers memory boundary violations and unsafe memory management functions in compiled binaries.\n