TODDR YAML::Syck up to 1.37 on Perl perl_syck.h buffer underflow

Summaryinfo

A vulnerability was found in TODDR YAML::Syck up to 1.37 on Perl. It has been classified as problematic. The impacted element is an unknown function of the file perl_syck.h. The manipulation leads to buffer underflow. This vulnerability is referenced as CVE-2026-5089. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in TODDR YAML::Syck up to 1.37 on Perl. It has been rated as problematic. This issue affects an unknown code block of the file perl_syck.h. The manipulation with an unknown input leads to a buffer underflow vulnerability. Using CWE to declare the problem leads to CWE-124. The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer. Impacted is availability. The summary by CVE is:

YAML::Syck versions before 1.38 for Perl has an out-of-bounds read. The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer: while ( colon >= ptr && *colon != ':' ) { colon--; } if ( *colon == ':' ) *colon = '\0'; // colon may be ptr-1 here When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer.

It is possible to read the advisory at metacpan.org. The identification of this vulnerability is CVE-2026-5089 since 03/28/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 321002 (openSUSE 16 Security Update : perl-YAML-Syck (openSUSE-SU-2026:20938-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.38 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (321002). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• TODDR

Name

• YAML::Syck

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.26
• 1.27
• 1.28
• 1.29
• 1.30
• 1.31
• 1.32
• 1.33
• 1.34
• 1.35
• 1.36
• 1.37

CPE 2.3info

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CPE 2.2info

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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