CVE-2026-4177
Heap Buffer Overflow in YAML::Syck Perl Emitter Causes High Severity Risk
Publication date: 2026-03-16
Last updated on: 2026-03-23
Assigner: CPANSec
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| toddr | yaml | to 1.37 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-122 | A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects YAML::Syck versions through 1.36 for Perl and includes several potential security issues. One high-severity issue is a heap buffer overflow in the YAML emitter that happens when class names exceed the initially allocated 512 bytes. Additionally, the base64 decoder can read beyond the buffer end when trailing newlines are present. There is also a problem where strtok mutates the type_id in place, corrupting shared node data. Lastly, a memory leak occurs in the function syck_hdlr_add_anchor when a node already has an anchor, causing the incoming anchor string to be leaked on early return.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know
How can this vulnerability impact me? :
The heap buffer overflow can lead to memory corruption, which may allow an attacker to execute arbitrary code or cause a denial of service. The base64 decoder reading past buffer boundaries could also result in unexpected behavior or crashes. Corruption of shared node data due to strtok mutation can cause data integrity issues or application instability. The memory leak may lead to increased memory usage over time, potentially degrading system performance.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know