CVE-2026-8657

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-05-16. NVD baseline CVSS 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
8.2
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.2Exploit: NoneExposed: 0

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

Versions of the package jsondiffpatch before 0.7.6 are vulnerable to Prototype Pollution via the jsondiffpatch.patch() and jsondiffpatch/formatters/jsonpatch.patch() APIs. An attacker can perform prototype pollution by supplying crafted delta or JSON Patch documents, as attacker-controlled property names and path segments are used to traverse and modify objects without restricting access to special properties like __proto__ or constructor.prototype, allowing modification of Object.prototype.

CVSS v3
8.2
EG Score
8.2(medium)
EPSS
29.9%
KEV
Not listed

Published

May 16, 2026

Last Modified

July 5, 2026

Advisory Details (3)

Auto-updated May 16, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Prototype Pollution in jsondiffpatch | CVE-2026-8657 | Snyk

https://security.snyk.io/vuln/SNYK-JS-JSONDIFFPATCH-16322990
generic

fix: prevent prototype pollution in patch, unpatch, reverse, and JSON… · benjamine/jsondiffpatch@381c012 · GitHub

https://github.com/benjamine/jsondiffpatch/commit/381c0125efab49f6f0dbc08317d01d55717672af
generic

Prototype Pollution in jsondiffpatch delta and JSON Patch application · GitHub

https://gist.github.com/yuki-matsuhashi/e570fb1579ae1f3190059b622b0473fb

Vendor Advisories for CVE-2026-8657(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 10× in last 7d / 66× 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 130 total refreshes for this CVE.

  1. 2026-07-12 05:46 UTCEPSS rescore
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-09 19:10 UTCEPSS rescore
  4. 2026-07-08 15:16 UTCEPSS rescore
  5. 2026-07-07 13:46 UTCEPSS rescore
  6. 2026-07-06 16:27 UTCEPSS rescore
  7. 2026-07-06 16:27 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-06 02:23 UTCEPSS rescore
  10. 2026-07-05 17:59 UTCNVD updateCVSS v4 → 7.8
  11. 2026-07-05 02:31 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-01 15:07 UTCEPSS rescore
  16. 2026-06-30 23:22 UTCEPSS rescore
  17. 2026-06-29 21:21 UTCEG score recompute
  18. 2026-06-29 21:21 UTCGHSA enrichment
  19. 2026-06-29 14:06 UTCEPSS rescore
  20. 2026-06-28 14:07 UTCEPSS rescore
  21. 2026-06-28 11:23 UTCEG score recompute
  22. 2026-06-28 11:23 UTCGHSA enrichment
  23. 2026-06-28 04:56 UTCEPSS rescore
  24. 2026-06-27 22:18 UTCEG score recompute
  25. 2026-06-27 22:18 UTCGHSA enrichment
Show 75 more
  1. 2026-06-27 09:11 UTCEG score recompute
  2. 2026-06-27 09:11 UTCGHSA enrichment
  3. 2026-06-27 03:08 UTCEPSS rescore
  4. 2026-06-26 20:04 UTCEG score recompute
  5. 2026-06-26 20:04 UTCGHSA enrichment
  6. 2026-06-25 18:38 UTCEG score recompute
  7. 2026-06-25 18:38 UTCGHSA enrichment
  8. 2026-06-25 13:50 UTCEPSS rescore
  9. 2026-06-24 14:05 UTCEPSS rescore
  10. 2026-06-23 21:33 UTCEPSS rescore
  11. 2026-06-22 14:25 UTCEPSS rescore
  12. 2026-06-21 14:56 UTCEPSS rescore
  13. 2026-06-21 01:59 UTCEPSS rescore
  14. 2026-06-19 19:26 UTCEPSS rescore
  15. 2026-06-18 17:52 UTCEPSS rescore
  16. 2026-06-18 02:53 UTCEG score recompute
  17. 2026-06-18 02:53 UTCGHSA enrichment
  18. 2026-06-17 17:53 UTCEPSS rescore
  19. 2026-06-17 13:20 UTCEG score recompute
  20. 2026-06-17 13:20 UTCGHSA enrichment
  21. 2026-06-16 21:46 UTCEG score recompute
  22. 2026-06-16 21:46 UTCGHSA enrichment
  23. 2026-06-16 17:53 UTCEPSS rescore
  24. 2026-06-15 23:24 UTCEG score recompute
  25. 2026-06-15 23:24 UTCGHSA enrichment
  26. 2026-06-15 17:49 UTCEPSS rescore
  27. 2026-06-15 17:49 UTCEPSS rescore
  28. 2026-06-15 01:19 UTCEG score recompute
  29. 2026-06-15 01:18 UTCGHSA enrichment
  30. 2026-06-14 23:18 UTCEPSS rescore
  31. 2026-06-14 12:13 UTCEG score recompute
  32. 2026-06-14 12:13 UTCGHSA enrichment
  33. 2026-06-13 23:09 UTCEG score recompute
  34. 2026-06-13 23:09 UTCGHSA enrichment
  35. 2026-06-13 23:00 UTCEPSS rescore
  36. 2026-06-13 05:17 UTCEG score recompute
  37. 2026-06-13 05:17 UTCGHSA enrichment
  38. 2026-06-12 23:12 UTCEPSS rescore
  39. 2026-06-12 23:12 UTCEPSS rescore
  40. 2026-06-12 16:10 UTCEG score recompute
  41. 2026-06-12 16:10 UTCGHSA enrichment
  42. 2026-06-12 02:50 UTCEG score recompute
  43. 2026-06-12 02:50 UTCGHSA enrichment
  44. 2026-06-11 14:00 UTCEPSS rescore
  45. 2026-06-11 13:46 UTCEG score recompute
  46. 2026-06-11 13:46 UTCGHSA enrichment
  47. 2026-06-11 00:42 UTCEG score recompute
  48. 2026-06-11 00:42 UTCGHSA enrichment
  49. 2026-06-10 22:19 UTCEPSS rescore
  50. 2026-06-10 13:22 UTCEPSS rescore
  51. 2026-06-10 11:38 UTCEG score recompute
  52. 2026-06-10 11:38 UTCGHSA enrichment
  53. 2026-06-09 22:34 UTCEG score recompute
  54. 2026-06-09 22:34 UTCGHSA enrichment
  55. 2026-06-09 09:30 UTCEG score recompute
  56. 2026-06-09 09:30 UTCGHSA enrichment
  57. 2026-06-08 20:24 UTCEG score recompute
  58. 2026-06-08 20:24 UTCGHSA enrichment
  59. 2026-06-08 14:17 UTCEPSS rescore
  60. 2026-06-08 07:20 UTCEG score recompute
  61. 2026-06-08 07:20 UTCGHSA enrichment
  62. 2026-06-07 18:16 UTCEG score recompute
  63. 2026-06-07 18:16 UTCGHSA enrichment
  64. 2026-06-07 15:25 UTCEPSS rescore
  65. 2026-06-07 05:12 UTCEG score recompute
  66. 2026-06-07 05:12 UTCGHSA enrichment
  67. 2026-06-06 16:08 UTCEG score recompute
  68. 2026-06-06 16:08 UTCGHSA enrichment
  69. 2026-06-06 13:47 UTCEPSS rescore
  70. 2026-06-06 03:03 UTCEG score recompute
  71. 2026-06-06 03:03 UTCGHSA enrichment
  72. 2026-06-05 22:47 UTCEPSS rescore
  73. 2026-06-05 13:58 UTCEG score recompute
  74. 2026-06-05 13:58 UTCGHSA enrichment
  75. 2026-06-05 06:10 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8657?
CVE-2026-8657 is a high vulnerability published on May 16, 2026. Versions of the package jsondiffpatch before 0.7.6 are vulnerable to Prototype Pollution via the jsondiffpatch.patch() and jsondiffpatch/formatters/jsonpatch.patch() APIs. An attacker can perform prototype pollution by supplying crafted delta or JSON Patch documents, as attacker-controlled property…
When was CVE-2026-8657 disclosed?
CVE-2026-8657 was first published in the National Vulnerability Database on May 16, 2026, with the most recent update on July 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8657 actively exploited?
CVE-2026-8657 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 29.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8657?
CVE-2026-8657 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-8657?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8657, 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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