CVE-2017-20285
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.1
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes
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.
- Record
CVE-2017-20285- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-502, CWE-470
- Updated
- 2026-11-02
EUVDEUVD-2017-19016
9.1
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.
- Record
EUVD-2017-19016- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-c454-fc94-q86x
9.1
YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of...
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.
- Record
GHSA-c454-fc94-q86x- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-470
- Updated
- 2026-11-02
NVD
9.1
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.
- Record
CVE-2017-20285- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-470, CWE-502
- Updated
- 2026-11-02
OSV
9.1
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.
- Record
CVE-2017-20285- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
OSVDEBIAN-CVE-2017-20285
9.1
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.
- Record
DEBIAN-CVE-2017-20285- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
Show 5 moreShow less
OSVRLSA-2026:93471
8.1
Important: perl-YAML:1.24 security update
he perl-YAML package provides the pure-Perl implementation of the YAML (YAML Ain't Markup Language) data serialization standard. It allows developers to serialize Perl data structures into formatted YAML text and deserialize YAML data back into native Perl structures, making it widely used for configuration files, data exchange, and human-readable data storage in Perl applications.
Security Fix(es):
-
perl-yaml: perl-yaml: Arbitrary code execution via unrestricted package variable assignment (CVE-2019-25777)
-
perl-yaml: perl-yaml: Arbitrary destructor method execution via crafted YAML document (CVE-2017-20285)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
- Record
RLSA-2026:93471- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSVUBUNTU-CVE-2017-20285
9.1
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.
- Record
UBUNTU-CVE-2017-20285- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
OSVALSA-2026:93471 No score
Important: perl-YAML:1.24 security update
he perl-YAML package provides the pure-Perl implementation of the YAML (YAML Ain't Markup Language) data serialization standard. It allows developers to serialize Perl data structures into formatted YAML text and deserialize YAML data back into native Perl structures, making it widely used for configuration files, data exchange, and human-readable data storage in Perl applications.
Security Fix(es):
- perl-yaml: perl-yaml: Arbitrary code execution via unrestricted package variable assignment (CVE-2019-25777)
- perl-yaml: perl-yaml: Arbitrary destructor method execution via crafted YAML document (CVE-2017-20285)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
- Record
ALSA-2026:93471- Updated
- 2026-11-03
OSVopenSUSE-SU-2026:12368-1 No score
perl-YAML-1.321.0-2.1 on GA media
These are all security issues fixed in the perl-YAML-1.321.0-2.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12368-1- Updated
- 2026-11-02
OSVUSN-8925-1 No score
libyaml-perl vulnerabilities
Dominique Dumont discovered that YAML-LibYAML did not correctly handle certain reflection operations. If a user or system were tricked into opening a specially crafted file, an attacker could possibly use this issue to delete files. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2017-20285)
It was discovered that YAML-LibYAML did not correctly handle parsing certain documents. If a user or automated system were tricked into opening a specially crafted file, an attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-25777)
It was discovered that YAML-LibYAML contained a regular expression susceptible to catastrophic backtracking. If a user or automated system were tricked into opening a specially crafted file, an attacker could possibly use this issue to cause a denial of service. (CVE-2026-63676)
- Record
USN-8925-1- Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
perl-YAMLAlmaLinux:8 From an advisory covering 2 CVEs |
before 1.24-4.module_el8.10.0+4341+ab0ec422 | 1.24-4.module_el8.10.0+4341+ab0ec422 |
libyaml-perlDebian:12 |
before 1.30-1 | 1.30-1 |
libyaml-perlDebian:13 |
before 1.30-1 | 1.30-1 |
libyaml-perlDebian:14 |
before 1.30-1 | 1.30-1 |
perl-YAMLRocky Linux:8 From an advisory covering 2 CVEs |
before 0:1.24-4.module+el8.10.0+40403+bd06a93a | 0:1.24-4.module+el8.10.0+40403+bd06a93a |
perl-YAMLRocky Linux:8 From an advisory covering 2 CVEs |
before 0:1.24-4.module+el8.10.0+40403+df14587c | 0:1.24-4.module+el8.10.0+40403+df14587c |
perl-YAMLRocky Linux:8 From an advisory covering 2 CVEs |
before 0:1.24-4.module+el8.10.0+40403+94558160 | 0:1.24-4.module+el8.10.0+40403+94558160 |
perl-YAMLRocky Linux:8 From an advisory covering 2 CVEs |
before 0:1.24-4.module+el8.10.0+40403+9457ea6c | 0:1.24-4.module+el8.10.0+40403+9457ea6c |
libyaml-perlUbuntu:Pro:16.04:LTS |
before 1.15-1ubuntu0.1~esm1, plus listed versions 1.13-11.15-1 |
1.15-1ubuntu0.1~esm1 |
libyaml-perlUbuntu:Pro:18.04:LTS |
before 1.24-1ubuntu0.1~esm1, plus listed versions 1.21-11.24-1 |
1.24-1ubuntu0.1~esm1 |
Show 7 moreShow less
| Package | Affected | Fixed |
|---|---|---|
libyaml-perlUbuntu:Pro:16.04:LTS From an advisory covering 3 CVEs |
before 1.15-1ubuntu0.1~esm1, plus listed versions 1.13-11.15-1 |
1.15-1ubuntu0.1~esm1 |
libyaml-perlUbuntu:Pro:18.04:LTS From an advisory covering 3 CVEs |
before 1.24-1ubuntu0.1~esm1, plus listed versions 1.21-11.24-1 |
1.24-1ubuntu0.1~esm1 |
libyaml-perlUbuntu:Pro:20.04:LTS From an advisory covering 3 CVEs |
before 1.30-1ubuntu0.20.04.1~esm1, plus listed versions 1.29-11.30-1 |
1.30-1ubuntu0.20.04.1~esm1 |
libyaml-perlUbuntu:22.04:LTS From an advisory covering 3 CVEs |
before 1.30-1ubuntu0.22.04.1, plus listed versions 1.30-1 |
1.30-1ubuntu0.22.04.1 |
libyaml-perlUbuntu:24.04:LTS From an advisory covering 3 CVEs |
before 1.31-1ubuntu0.24.04.1, plus listed versions 1.30-21.31-1 |
1.31-1ubuntu0.24.04.1 |
libyaml-perlUbuntu:Pro:26.04:LTS From an advisory covering 3 CVEs |
before 1.31-1ubuntu0.26.04.1~esm1, plus listed versions 1.31-1 |
1.31-1ubuntu0.26.04.1~esm1 |
perl-YAMLopenSUSE:Tumbleweed From an advisory covering 2 CVEs |
before 1.321.0-2.1 | 1.321.0-2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected, aliases, references | OSV | |
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2017-20285 is a critical vulnerability (CVSS 9.1) in perl-YAML, published October 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. Fixed in libyaml-perl 1.30-1.
References
github.com/ingydotnet/yaml-pm/issues/176
github.com/ingydotnet/yaml-pm/commit/471314bbdcbd62077eea32755929122aa8bd00a3.patch
github.com/ingydotnet/yaml-pm/commit/7736f38bd02e4f9f77d5468721e3be3d7b34a8ec.patch
metacpan.org/release/TINITA/YAML-1.30/changes
openwall.com/lists/oss-security/2026/10/05/8
nvd.nist.gov/vuln/detail/CVE-2017-20285
Show 19 moreShow less
github.com/advisories/GHSA-c454-fc94-q86x
access.redhat.com/errata/RHSA-2026:93471
access.redhat.com/security/cve/CVE-2017-20285
access.redhat.com/security/cve/CVE-2019-25777
bugzilla.redhat.com/2545818
bugzilla.redhat.com/2545820
errata.almalinux.org/8/ALSA-2026-93471.html
security-tracker.debian.org/tracker/CVE-2017-20285
errata.rockylinux.org/RLSA-2026:93471
bugzilla.redhat.com/show_bug.cgi?id=2545818
bugzilla.redhat.com/show_bug.cgi?id=2545820
ubuntu.com/security/CVE-2017-20285
cve.org/CVERecord?id=CVE-2017-20285
blogs.perl.org/users/tinita/2020/01/making-yamlpm-yamlsyck-and-yamlxs-safer-by-default.html
ubuntu.com/security/notices/USN-8925-1
ubuntu.com/security/CVE-2019-25777
ubuntu.com/security/CVE-2026-63676
suse.com/security/cve/CVE-2017-20285
suse.com/security/cve/CVE-2019-25777