CVE-2017-18342: fedoraproject fedora Deserialization of Untrusted Data
Vulnerability summary
CVE-2017-18342 is a critical (CVSS 9.8) Deserialization of Untrusted Data vulnerability in fedoraproject fedora. EPSS estimates a 5.57% chance of exploitation in the next 30 days, higher than 92.8% of scored vulnerabilities.
Severe, CVSS 9.8 (NVD); no exploitation reported by the 5 checked sources; EPSS 6% (FIRST, 04-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 4 · Related 4Timeline
- 27-06-2018PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
Description
In PyYAML before 5.1, the yaml.load() API could execute arbitrary code if used with untrusted data. The load() function has been deprecated in version 5.1 and the 'UnsafeLoader' has been introduced for backward compatibility with the function.
CVSS metrics
6 scores · 4 sources · 3 versions- OSV · PypiEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
5.57%
Chance of exploitation in the next 30 days
Percentile
93%
Versus all other CVEs
30-day change
Decrease -0.09 pp
From 5.66% on 05-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- pyyaml< 5.1.2-1
Fedoraproject1 product
- fedoraEOL28 | 29 | 30
Mageia1 product
- python-yaml< 5.1-1.1.mga6
Opensuse1 product
- python-openapi-spec-validator&distro=openSUSE Tumbleweed< 0.7.1-1.3 | < 0.9.0-1.1
PyPI1 product
- pyyaml< 5.1
Pyyaml1 product
- pyyaml< 5.1
Ubuntu1 product
- pyyamlAll versions (No fix recorded)
7 vendors · 7 products
References
29 linksShow all 29 references
- github.com/yaml/pyyamlPACKAGE
