CVE-2017-20285
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes
CVSS v3
9.1
CRITICAL
EPSS Score
0.2 %
exploit probability, as of 2026-10-05
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes. A perl/hash:Class tag blesses a hash into the class it names. The document supplies the object's fields, and Perl calls DESTROY when it goes out of scope. What DESTROY does depends on the classes the process has loaded. With File::Temp::Dir from core Perl, it can delete a directory tree the document names.
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Published
- 2026-10-05
- Last Modified
- 2026-10-06
Frequently asked questions
What is CVE-2017-20285?
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes. A perl/hash:Class tag blesses a hash into the class it names. The document supplies the object's fields, and Perl calls DESTROY when it goes out of scope. What DESTROY does depends on the classes the process has loaded. With File::Temp::Dir from core Perl, it can delete a directory tree the document names.
Is CVE-2017-20285 actively exploited?
Active exploitation of CVE-2017-20285 has not been confirmed. Its EPSS score was 0.2% on 2026-10-05, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2017-20285?
CVE-2017-20285 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
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