An undocumented and unsafe feature in the PLY (Python Lex-Yacc) library 3.11 allows…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-502.
Summary
An undocumented and unsafe feature in the PLY (Python Lex-Yacc) library 3.11 allows Remote Code Execution (RCE) via the `picklefile` parameter in the `yacc()` function. This parameter accepts a `.pkl` file that is deserialized with `pickle.load()` without validation. Because `pickle` allows execution of embedded code via `__reduce__()`, an attacker can achieve code execution by passing a malicious pickle file. The parameter is not mentioned in official documentation or the GitHub repository, yet it is active in the PyPI version. This introduces a stealthy backdoor and persistence risk. NOTE: A third-party states that this vulnerability should be rejected because the proof of concept does not demonstrate arbitrary code execution and fails to complete successfully.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Migration Toolkit for Containers | Affected | No fix planned: Will not fix |
| Migration Toolkit for Virtualization | Affected | No fix planned: Will not fix |
| OpenShift Developer Tools and Services | Affected | No fix yet |
| OpenShift Pipelines | Affected | No fix planned: Will not fix |
| Red Hat Advanced Cluster Security 4 | Affected | No fix planned: Will not fix |
| Red Hat Ceph Storage 7 | Affected | No fix yet |
| Red Hat Ceph Storage 8 | Affected | No fix yet |
| Red Hat Certification Program for Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Directory Server 13 | Affected | No fix yet |
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix planned: Will not fix |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift GitOps | Affected | No fix planned: Will not fix |
| Red Hat Quay 3 | Affected | No fix yet |
| Service Telemetry Framework 1.5 | Affected | No fix yet |
Not affected: 19 products
- Fence Agents Remediation Operator
- Migration Toolkit for Containers
- OpenShift Developer Tools and Services
- OpenShift Service Mesh 2
- OpenShift Service Mesh 3
- Red Hat Ansible Automation Platform Ansible Core 2
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift GitOps
- Red Hat OpenStack Platform 13 (Queens)
- Red Hat OpenStack Platform 16.2
- Red Hat OpenStack Platform 17.1
- Red Hat OpenStack Platform 18.0
- Red Hat Openshift Data Foundation 4
- Red Hat Quay 3
- Service Telemetry Framework 1.5
Timeline
- 2026-10-02 Threatist record created from CVE-2025-56005
- 2026-10-03 Alias added: GHSA-qc6m-pwr3-g72p
- 2026-10-19 Affected versions changed · Red Hat
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 Affected versions changed · Red Hat
References
Exploit 6
- https://github.com/bohmiiidd/Undocumented-RCE-in-PLY
- https://github.com/tom025/ply_exploit_rejection
- https://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005
- http://www.openwall.com/lists/oss-security/2026/01/23/4
- http://www.openwall.com/lists/oss-security/2026/01/28/5
- http://www.openwall.com/lists/oss-security/2026/01/29/1
Sources
- CVE-2025-56005 · CVE Program
- CVE-2025-56005 · NVD
- FIRST EPSS
- GHSA-qc6m-pwr3-g72p · GitHub Advisory Database · CC BY 4.0
- CVE-2025-56005 · Red Hat security data · CC BY 4.0
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