CVE-2019-25777
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
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
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
CVE-2019-25777- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-914, CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2019-20205
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
EUVD-2019-20205- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-38xx-2hm6-vh7q
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package...
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
GHSA-38xx-2hm6-vh7q- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-502
- Updated
- 2026-11-02
NVD
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
CVE-2019-25777- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-502, CWE-914
- Updated
- 2026-11-02
OSV
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
CVE-2019-25777- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-03
OSVDEBIAN-CVE-2019-25777
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution. A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options. A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
DEBIAN-CVE-2019-25777- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - 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-2019-25777
7.3
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution. A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options. A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Record
UBUNTU-CVE-2019-25777- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - 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 1.29-1 | 1.29-1 |
libyaml-perlDebian:13 |
before 1.29-1 | 1.29-1 |
libyaml-perlDebian:14 |
before 1.29-1 | 1.29-1 |
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-2019-25777 is a high vulnerability (CVSS 7.3) 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 0.35%, the 29th percentile. Fixed in libyaml-perl 1.29-1.
References
github.com/ingydotnet/yaml-pm/issues/212
github.com/ingydotnet/yaml-pm/commit/bace96b5e6661d521c7c515c94a09e081c911fce.patch
metacpan.org/release/TINITA/YAML-1.28/changes
openwall.com/lists/oss-security/2026/10/05/7
nvd.nist.gov/vuln/detail/CVE-2019-25777
github.com/advisories/GHSA-38xx-2hm6-vh7q
Show 17 moreShow less
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-2019-25777
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-2019-25777
cve.org/CVERecord?id=CVE-2019-25777
ubuntu.com/security/notices/USN-8925-1
ubuntu.com/security/CVE-2017-20285
ubuntu.com/security/CVE-2026-63676
suse.com/security/cve/CVE-2017-20285
suse.com/security/cve/CVE-2019-25777