Prototype pollution in jsondiffpatch
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
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 |
|---|---|---|---|---|---|
| — | jsondiffpatch | before 0.7.6 | 0.7.6 | Patch available | CNA |
| — | org.webjars.npm:jsondiffpatch | all versions | — | No fix listed | CNA |
| — | jsondiffpatch (npm) | before 0.7.6 | 0.7.6 | Patch available | GHSA-j4fx-xxwh-2485 |
- jsondiffpatch Vendor— Affected before 0.7.6 Fixed in 0.7.6 Patch available CNA
- org.webjars.npm:jsondiffpatch Vendor— Affected all versions Fixed in — No fix listed CNA
- jsondiffpatch (npm) Vendor— Affected before 0.7.6 Fixed in 0.7.6 Patch available GHSA-j4fx-xxwh-2485
Remediation
- Fix · CNA jsondiffpatch Fixed in 0.7.6
- Fix · GHSA-j4fx-xxwh-2485 jsondiffpatch (npm) Fixed in 0.7.6 Advisory →
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
jsondiffpatch 0.7.6
2 records Highest priority Priority HIGH 1 HIGH, 1 MEDIUM
Other records, highest priority first
- TI-2026-07605 Cross-site scripting in jsondiffpatchPriority MEDIUM 56
Timeline
- 2026-10-02 Threatist record created from CVE-2026-8657
- 2026-10-03 Alias added: GHSA-j4fx-xxwh-2485
- 2026-10-25 EPSS moved to the below the 50th percentile
References
Other 7
- https://gist.github.com/yuki-matsuhashi/e570fb1579ae1f3190059b622b0473fb
- https://github.com/benjamine/jsondiffpatch/blob/96112c35a98f9201dd75d67fcee68a952c79e2fe/packages/jsondiffpatch/src/filters/nested.ts%23L82-L87
- https://github.com/benjamine/jsondiffpatch/blob/96112c35a98f9201dd75d67fcee68a952c79e2fe/packages/jsondiffpatch/src/filters/nested.ts%23L107-L115
- https://github.com/benjamine/jsondiffpatch/blob/96112c35a98f9201dd75d67fcee68a952c79e2fe/packages/jsondiffpatch/src/formatters/jsonpatch-apply.ts%23L146-L168
- https://github.com/benjamine/jsondiffpatch/blob/96112c35a98f9201dd75d67fcee68a952c79e2fe/packages/jsondiffpatch/src/formatters/jsonpatch-apply.ts%23L171-L199
- https://github.com/benjamine/jsondiffpatch/commit/381c0125efab49f6f0dbc08317d01d55717672af
- https://github.com/benjamine/jsondiffpatch
Sources
- CVE-2026-8657 · CVE Program
- CVE-2026-8657 · NVD
- FIRST EPSS
- GHSA-j4fx-xxwh-2485 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences