Information disclosure via unterminated lexer buffers
Published Oct 16, 2025 · Updated Oct 16, 2025
Out-of-bounds read in Todd Rinaldo YAML::Syck before 1.36 allows attackers to disclose adjacent parser data via crafted YAML. In token.c, several lexer paths allocate qstr without writing an initial null terminator, so parsing hash keys with empty values treats uninitialized adjacent bytes as string data. Exploitation requires an application to parse the crafted document, and the reported disclosure remains within memory allocated to the module.
Summary
What happened
Out-of-bounds read in Todd Rinaldo YAML::Syck before 1.36 allows attackers to disclose adjacent parser data via crafted YAML. In token.c, several lexer paths allocate qstr without writing an initial null terminator, so parsing hash keys with empty values treats uninitialized adjacent bytes as string data. Exploitation requires an application to parse the crafted document, and the reported disclosure remains within memory allocated to the module.
The record
- CVE
- CVE-2025-11683
- Published
- Oct 16, 2025
- Updated
- Oct 16, 2025
- Vendor
- Todd Rinaldo
- Product
- YAML::Syck
- Classifications
- CWE-119, CAPEC-540
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 16, 2025CVE publishedPublication date reported by the CVE source.
- Oct 16, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.36
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo