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
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 19%CVSS: 9.8Exploit: Elevated riskExposed: 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 PROB
19%
EPSS %ILE
97%
KEV
Not listed

Published

January 20, 2026

Last Modified

September 17, 2026

Advisory Details (10)

Auto-updated Sep 17, 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/Undocumented-RCE-in-PLY: Undocumented RCE in PLY via `picklefile` Parameter · GitHub

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

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.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
ply3.11-10 ... 3.11-9 (8 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
ply3.11-10 ... 3.11-9 (8 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
ply3.11-10, 3.11-11, 3.11-12, 3.11-9——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
ply3.11-10, 3.11-11, 3.11-12, 3.11-9——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 35× 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.

Showing the most recent 100 of 167 total refreshes for this CVE.

  1. 2026-09-19 15:42 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-18 19:27 UTCEPSS rescore
  4. 2026-09-17 19:29 UTCEPSS rescore
  5. 2026-09-17 12:19 UTCGHSA enrichment
  6. 2026-09-17 12:12 UTCEG score recompute
  7. 2026-09-17 12:12 UTCGHSA enrichment
  8. 2026-09-16 14:07 UTCEPSS rescore
  9. 2026-09-16 05:14 UTCEPSS rescore
  10. 2026-09-12 15:00 UTCEPSS rescore
  11. 2026-09-11 14:52 UTCEPSS rescore
  12. 2026-09-11 09:36 UTCEPSS rescore
  13. 2026-09-10 09:34 UTCEPSS rescore
  14. 2026-09-08 21:59 UTCEPSS rescore
  15. 2026-09-07 16:00 UTCEPSS rescore
  16. 2026-09-06 13:47 UTCEPSS rescore
  17. 2026-09-05 15:28 UTCEPSS rescore
  18. 2026-09-04 05:06 UTCEPSS rescore
  19. 2026-09-02 14:11 UTCEPSS rescore
  20. 2026-09-01 13:53 UTCEPSS rescore
  21. 2026-09-01 12:25 UTCEG score recompute
  22. 2026-09-01 12:25 UTCGHSA enrichment
  23. 2026-09-01 04:38 UTCEPSS rescore
  24. 2026-08-30 19:16 UTCEPSS rescore
  25. 2026-08-30 01:21 UTCEPSS rescore
Show 75 more
  1. 2026-08-28 21:40 UTCEPSS rescore
  2. 2026-08-27 14:24 UTCEPSS rescore
  3. 2026-08-26 14:45 UTCEPSS rescore
  4. 2026-08-25 13:48 UTCEPSS rescore
  5. 2026-08-24 14:16 UTCEPSS rescore
  6. 2026-08-24 13:32 UTCGHSA enrichment
  7. 2026-08-24 12:28 UTCEG score recompute
  8. 2026-08-24 12:28 UTCGHSA enrichment
  9. 2026-08-24 09:22 UTCEPSS rescore
  10. 2026-08-23 00:18 UTCEPSS rescore
  11. 2026-08-21 23:48 UTCEPSS rescore
  12. 2026-08-20 22:54 UTCEPSS rescore
  13. 2026-08-19 17:03 UTCEPSS rescore
  14. 2026-08-18 13:47 UTCEPSS rescore
  15. 2026-08-16 14:55 UTCEPSS rescore
  16. 2026-08-16 02:13 UTCEPSS rescore
  17. 2026-08-15 01:29 UTCEPSS rescore
  18. 2026-08-14 23:21 UTCGHSA enrichment
  19. 2026-08-14 13:35 UTCEG score recompute
  20. 2026-08-14 13:35 UTCGHSA enrichment
  21. 2026-08-13 21:59 UTCEPSS rescore
  22. 2026-08-13 12:29 UTCEG score recompute
  23. 2026-08-13 12:29 UTCGHSA enrichment
  24. 2026-08-12 13:50 UTCEPSS rescore
  25. 2026-08-12 13:50 UTCEPSS rescore
  26. 2026-08-11 13:42 UTCEPSS rescore
  27. 2026-08-09 22:47 UTCGHSA enrichment
  28. 2026-08-09 19:10 UTCEG score recompute
  29. 2026-08-09 19:10 UTCGHSA enrichment
  30. 2026-08-08 16:36 UTCEPSS rescore
  31. 2026-08-08 07:37 UTCGHSA enrichment
  32. 2026-08-08 03:59 UTCGHSA enrichment
  33. 2026-08-08 00:10 UTCEG score recompute
  34. 2026-08-08 00:10 UTCGHSA enrichment
  35. 2026-08-07 16:26 UTCEPSS rescore
  36. 2026-08-07 12:26 UTCGHSA enrichment
  37. 2026-08-07 12:09 UTCEG score recompute
  38. 2026-08-07 12:09 UTCGHSA enrichment
  39. 2026-08-06 13:46 UTCEPSS rescore
  40. 2026-08-06 09:04 UTCGHSA enrichment
  41. 2026-08-06 05:26 UTCEG score recompute
  42. 2026-08-06 05:26 UTCGHSA enrichment
  43. 2026-08-05 19:16 UTCEPSS rescore
  44. 2026-08-05 12:46 UTCEG score recompute
  45. 2026-08-05 12:46 UTCGHSA enrichment
  46. 2026-08-04 15:09 UTCEPSS rescore
  47. 2026-08-04 15:09 UTCEPSS rescore
  48. 2026-08-03 10:35 UTCEPSS rescore
  49. 2026-08-02 22:50 UTCEG score recompute
  50. 2026-08-02 22:50 UTCGHSA enrichment
  51. 2026-08-01 04:15 UTCEPSS rescore
  52. 2026-07-30 16:27 UTCEPSS rescore
  53. 2026-07-30 01:30 UTCEPSS rescore
  54. 2026-07-28 15:35 UTCEPSS rescore
  55. 2026-07-26 14:54 UTCEPSS rescore
  56. 2026-07-25 14:17 UTCEPSS rescore
  57. 2026-07-24 14:17 UTCEPSS rescore
  58. 2026-07-23 14:18 UTCEPSS rescore
  59. 2026-07-23 10:19 UTCOSV refresh
  60. 2026-07-23 02:59 UTCEG score recompute
  61. 2026-07-22 14:08 UTCEPSS rescore
  62. 2026-07-22 14:07 UTCEPSS rescore
  63. 2026-07-21 15:24 UTCEPSS rescore
  64. 2026-07-20 17:08 UTCEPSS rescore
  65. 2026-07-19 14:30 UTCEPSS rescore
  66. 2026-07-19 14:30 UTCEPSS rescore
  67. 2026-07-19 02:28 UTCEPSS rescore
  68. 2026-07-18 10:04 UTCEPSS rescore
  69. 2026-07-16 17:02 UTCEPSS rescore
  70. 2026-07-15 16:57 UTCEPSS rescore
  71. 2026-07-15 16:57 UTCEPSS rescore
  72. 2026-07-15 01:59 UTCEPSS rescore
  73. 2026-07-15 01:59 UTCEPSS rescore
  74. 2026-07-13 22:29 UTCEPSS rescore
  75. 2026-07-13 06:12 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 September 17, 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 19% probability of exploitation in the next 30 days, which ranks it in the top 2.8% of all scored CVEs.
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.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-56005

Explore →

Is Your Infrastructure Affected by CVE-2025-56005?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs