CVE-2026-9856

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

Score 7.1 from GitHub Security Advisory (severity: HIGH) published 2026-08-02. A secondary CVSS source baseline 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A vulnerability in huggingface/transformers versions <=5.8.0.dev0 allows an attacker to perform arbitrary file writes via path traversal. The issue resides in the save_pretrained() methods of PreTrainedTokenizerBase and ProcessorMixin, where keys from the chat_template dictionary are used directly as filenames without proper validation. An attacker can exploit this by publishing a malicious Hugging Face Hub repository with a crafted tokenizer_config.json file. When a victim downloads and saves the tokenizer or processor, the attacker-controlled keys can escape the intended save directory, enabling arbitrary file writes with attacker-controlled content. This vulnerability affects multiple processors inheriting from ProcessorMixin, including Idefics, Florence, Gemma, Phi, and Qwen-VL.

CVSS v3
7.1
EG Score
7.1HIGHmedium confidence
EG Risk
32
EG Risk 32/100CISA SSVC

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
Severity71% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
37th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 2, 2026

Last Modified

September 3, 2026

Advisory Details (1)

Auto-updated Aug 2, 2026
Patch available. Sources: github_commit.
github_commit

commit eaaaf8494dd5 (huggingface/transformers)

Fix landed in huggingface/transformers commit eaaaf8494dd5 — awaiting tagged release

https://github.com/huggingface/transformers/commit/eaaaf8494dd5386634ae37d1d122212fdc315be5

Vendor Advisories for CVE-2026-9856(1)

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

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
transformers0.1 ... 5.9.0 (226 versions)
  • every version up to 5.10.0: fixed in 5.10.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 53× 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 179 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-9856?
CVE-2026-9856 is a high vulnerability published on August 2, 2026. A vulnerability in huggingface/transformers versions <=5.8.0.dev0 allows an attacker to perform arbitrary file writes via path traversal. The issue resides in the savepretrained() methods of PreTrainedTokenizerBase and ProcessorMixin, where keys from the chattemplate dictionary are used directly as…
When was CVE-2026-9856 disclosed?
CVE-2026-9856 was first published on August 2, 2026, with the most recent update on September 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9856 actively exploited?
CVE-2026-9856 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-9856?
CVE-2026-9856 has a CVSS base score of 7.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-9856?
A fix for CVE-2026-9856 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-9856 are linked in the Vendor Advisories panel on this page.

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