CVE-2025-56005

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-01-20. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 17%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS
96.7%
KEV
Not listed

Published

January 20, 2026

Last Modified

July 20, 2026

Advisory Details (10)

Auto-updated Jul 20, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

oss-security - Re: CVE-2025-56005 Undocumented RCE in PLY via `picklefile` Parameter

http://www.openwall.com/lists/oss-security/2026/01/30/1
generic

oss-security - Re: CVE-2025-56005 Undocumented RCE in PLY via `picklefile` Parameter

http://www.openwall.com/lists/oss-security/2026/01/29/2
generic🟡 PoC Available

oss-security - Re: CVE-2025-56005 Undocumented RCE in PLY via `picklefile` Parameter

http://www.openwall.com/lists/oss-security/2026/01/29/1
generic🟡 PoC Available

oss-security - Re: CVE-2025-56005 Undocumented RCE in PLY via `picklefile` Parameter

http://www.openwall.com/lists/oss-security/2026/01/28/5
generic

oss-security - Re: CVE-2025-56005 Undocumented RCE in PLY via `picklefile` Parameter

http://www.openwall.com/lists/oss-security/2026/01/23/5
generic🟡 PoC Available

oss-security - CVE-2025-56005 Undocumented RCE in PLY via `picklefile` Parameter

http://www.openwall.com/lists/oss-security/2026/01/23/4
generic

Clarification: Unsafe pickle deserialization in PLY yacc() is RCE (CVE‑2025‑56005) · Issue #1 · tom025/ply_exploit_rejection · GitHub

https://github.com/tom025/ply_exploit_rejection/issues/1
generic🟡 PoC Available

GitHub - tom025/ply_exploit_rejection: Arguments to reject CVE-2025-56005 · GitHub

https://github.com/tom025/ply_exploit_rejection
generic🟡 PoC Available

GitHub - bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005: Clarification Regarding the Rejection Arguments · GitHub

https://github.com/bohmiiidd/Undocumument_RCE_PLY-yacc-CVE-2025-56005
generic🟡 PoC Available

GitHub - bohmiiidd/Undocumented-RCE-in-PLY: Undocumented RCE in PLY via `picklefile` Parameter · GitHub

https://github.com/bohmiiidd/Undocumented-RCE-in-PLY

Vendor Advisories for CVE-2025-56005(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-25 14:17 UTCEPSS rescore
  2. 2026-07-24 14:17 UTCEPSS rescore
  3. 2026-07-23 14:18 UTCEPSS rescore
  4. 2026-07-23 10:19 UTCOSV refresh
  5. 2026-07-23 02:59 UTCEG score recompute
  6. 2026-07-22 14:08 UTCEPSS rescore
  7. 2026-07-22 14:07 UTCEPSS rescore
  8. 2026-07-21 15:24 UTCEPSS rescore
  9. 2026-07-20 17:08 UTCEPSS rescore
  10. 2026-07-19 14:30 UTCEPSS rescore
  11. 2026-07-19 14:30 UTCEPSS rescore
  12. 2026-07-19 02:28 UTCEPSS rescore
  13. 2026-07-18 10:04 UTCEPSS rescore
  14. 2026-07-16 17:02 UTCEPSS rescore
  15. 2026-07-15 16:57 UTCEPSS rescore
  16. 2026-07-15 16:57 UTCEPSS rescore
  17. 2026-07-15 01:59 UTCEPSS rescore
  18. 2026-07-15 01:59 UTCEPSS rescore
  19. 2026-07-13 22:29 UTCEPSS rescore
  20. 2026-07-13 06:12 UTCEPSS rescore
  21. 2026-07-13 06:12 UTCEPSS rescore
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 08:27 UTCEPSS rescore
  24. 2026-07-11 08:27 UTCEPSS rescore
  25. 2026-07-09 19:09 UTCEPSS rescore
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  1. 2026-07-08 15:15 UTCEPSS rescore
  2. 2026-07-07 13:45 UTCEPSS rescore
  3. 2026-07-06 05:02 UTCOSV refresh
  4. 2026-07-05 02:30 UTCEPSS rescore
  5. 2026-07-02 17:01 UTCEPSS rescore
  6. 2026-07-01 15:06 UTCEPSS rescore
  7. 2026-06-30 23:22 UTCEPSS rescore
  8. 2026-06-28 14:07 UTCEPSS rescore
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 04:55 UTCEPSS rescore
  11. 2026-06-27 03:08 UTCEPSS rescore
  12. 2026-06-27 03:08 UTCEPSS rescore
  13. 2026-06-25 13:49 UTCEPSS rescore
  14. 2026-06-24 14:04 UTCEPSS rescore
  15. 2026-06-24 14:04 UTCEPSS rescore
  16. 2026-06-23 21:32 UTCEPSS rescore
  17. 2026-06-22 14:25 UTCEPSS rescore
  18. 2026-06-21 14:56 UTCEPSS rescore
  19. 2026-06-21 14:56 UTCEPSS rescore
  20. 2026-06-21 01:59 UTCEPSS rescore
  21. 2026-06-21 01:59 UTCEPSS rescore
  22. 2026-06-19 19:25 UTCEPSS rescore
  23. 2026-06-19 19:25 UTCEPSS rescore
  24. 2026-06-18 17:52 UTCEPSS rescore
  25. 2026-06-18 17:52 UTCEPSS rescore
  26. 2026-06-17 17:52 UTCEPSS rescore
  27. 2026-06-17 16:35 UTCOSV refresh
  28. 2026-06-16 17:52 UTCEPSS rescore
  29. 2026-06-16 17:52 UTCEPSS rescore
  30. 2026-06-15 17:48 UTCEPSS rescore
  31. 2026-06-14 23:17 UTCEPSS rescore
  32. 2026-06-13 23:00 UTCEPSS rescore
  33. 2026-06-12 23:11 UTCEPSS rescore
  34. 2026-06-11 14:00 UTCEPSS rescore
  35. 2026-06-11 14:00 UTCEPSS rescore
  36. 2026-06-10 22:18 UTCEPSS rescore
  37. 2026-06-10 22:18 UTCEPSS rescore
  38. 2026-06-10 13:22 UTCEPSS rescore
  39. 2026-06-10 13:22 UTCEPSS rescore
  40. 2026-06-08 14:16 UTCEPSS rescore
  41. 2026-06-08 14:16 UTCEPSS rescore
  42. 2026-06-07 15:24 UTCEPSS rescore
  43. 2026-06-07 15:24 UTCEPSS rescore
  44. 2026-06-06 13:47 UTCEPSS rescore
  45. 2026-06-06 13:47 UTCEPSS rescore
  46. 2026-06-05 22:46 UTCEPSS rescore
  47. 2026-06-05 22:46 UTCEPSS rescore
  48. 2026-06-05 06:10 UTCEPSS rescore
  49. 2026-06-05 06:10 UTCEPSS rescore
  50. 2026-06-04 13:12 UTCEPSS rescore
  51. 2026-06-04 13:12 UTCEPSS rescore
  52. 2026-06-02 20:12 UTCEPSS rescore
  53. 2026-06-02 20:12 UTCEPSS rescore
  54. 2026-06-01 13:51 UTCEPSS rescore
  55. 2026-06-01 13:51 UTCEPSS rescore
  56. 2026-05-31 22:30 UTCEPSS rescore
  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 00:16 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-29 15:35 UTCEG score recompute
  61. 2026-05-29 15:35 UTCGHSA enrichment
  62. 2026-05-29 13:44 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2025-56005?
CVE-2025-56005 is a critical vulnerability published on January 20, 2026. 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…
When was CVE-2025-56005 disclosed?
CVE-2025-56005 was first published in the National Vulnerability Database on January 20, 2026, with the most recent update on July 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-56005 actively exploited?
CVE-2025-56005 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 96.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-56005?
CVE-2025-56005 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2025-56005?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-56005, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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