Versions of the package ts-deepmerge before 8.0.0 are vulnerable to Uncaught Exception…
Priority HIGH 70CWE-248Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-248.
Summary
Versions of the package ts-deepmerge before 8.0.0 are vulnerable to Uncaught Exception due to the improper handling of built-in Object.prototype methods (such as toString, valueOf). When user-controlled input contains these keys with non-function values, the resulting merged object becomes broken — any string context operation throws a TypeError, crashing the application.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00507 43rd percentileScored 2026-11-07
Fix Fixed ts-deepmerge: 8.0.0ts-deepmerge (npm): 8.0.0
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 |
|---|---|---|---|---|---|
| — | ts-deepmerge | before 8.0.0 | 8.0.0 | Patch available | CNA |
| — | ts-deepmerge (npm) | before 8.0.0 | 8.0.0 | Patch available | GHSA-87mf-gv2c-c62c |
- ts-deepmerge Vendor— Affected before 8.0.0 Fixed in 8.0.0 Patch available CNA
- ts-deepmerge (npm) Vendor— Affected before 8.0.0 Fixed in 8.0.0 Patch available GHSA-87mf-gv2c-c62c
Remediation
- Fix · CNA ts-deepmerge Fixed in 8.0.0
- Fix · GHSA-87mf-gv2c-c62c ts-deepmerge (npm) Fixed in 8.0.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-12644
- 2026-10-03 Alias added: GHSA-87mf-gv2c-c62c
References
Sources
- CVE-2026-12644 · CVE Program
- CVE-2026-12644 · NVD
- FIRST EPSS
- GHSA-87mf-gv2c-c62c · GitHub Advisory Database · CC BY 4.0
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