CVE-2026-12644

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-06-19. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: None knownExposed: 0

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

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.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

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
Severity53% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
41%
KEV
Not listed

Published

June 19, 2026

Last Modified

June 23, 2026

Advisory Details (3)

Auto-updated Jun 22, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit.
generic

ts-deepmerge-prototype-method-override.md · GitHub

https://gist.github.com/igorg1312/775fa00114c4d47df6ae0551779ab407
generic🟡 PoC Available

Uncaught Exception in ts-deepmerge | CVE-2026-12644 | Snyk

https://security.snyk.io/vuln/SNYK-JS-TSDEEPMERGE-17339141
github_commit Patch Available

commit 305a05831a46 (voodoocreation/ts-deepmerge)

Patch available: voodoocreation/ts-deepmerge 8.0.0 (contains commit 305a05831a46)

https://github.com/voodoocreation/ts-deepmerge/commit/305a05831a462fb2c353d3cbbff55a0733286f8c

Vendor Advisories for CVE-2026-12644(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)
npm(1)
PackageVulnerable rangeFixed inDependents
ts-deepmerge—8.0.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 47× 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.

  1. 2026-08-25 13:48 UTCEPSS rescore
  2. 2026-08-25 01:30 UTCEG score recompute
  3. 2026-08-23 01:01 UTCEG score recompute
  4. 2026-08-23 00:19 UTCEPSS rescore
  5. 2026-08-21 23:48 UTCEPSS rescore
  6. 2026-08-21 08:22 UTCEG score recompute
  7. 2026-08-20 22:55 UTCEPSS rescore
  8. 2026-08-20 08:07 UTCEG score recompute
  9. 2026-08-19 17:03 UTCEPSS rescore
  10. 2026-08-19 07:21 UTCEG score recompute
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-16 21:20 UTCEG score recompute
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 21:06 UTCEG score recompute
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-14 20:12 UTCEG score recompute
  18. 2026-08-13 22:00 UTCEPSS rescore
  19. 2026-08-12 19:40 UTCEG score recompute
  20. 2026-08-12 13:50 UTCEPSS rescore
  21. 2026-08-11 19:26 UTCEG score recompute
  22. 2026-08-11 13:42 UTCEPSS rescore
  23. 2026-08-10 23:59 UTCEPSS rescore
  24. 2026-08-09 18:57 UTCEG score recompute
  25. 2026-08-09 13:46 UTCEPSS rescore
Show 65 more
  1. 2026-08-08 18:43 UTCEG score recompute
  2. 2026-08-08 16:37 UTCEPSS rescore
  3. 2026-08-07 18:28 UTCEG score recompute
  4. 2026-08-06 18:14 UTCEG score recompute
  5. 2026-08-06 13:46 UTCEPSS rescore
  6. 2026-08-05 19:17 UTCEPSS rescore
  7. 2026-08-04 15:22 UTCEG score recompute
  8. 2026-08-04 15:09 UTCEPSS rescore
  9. 2026-08-04 10:38 UTCEPSS rescore
  10. 2026-08-03 10:35 UTCEPSS rescore
  11. 2026-08-02 05:20 UTCEG score recompute
  12. 2026-08-02 02:26 UTCEPSS rescore
  13. 2026-08-01 05:06 UTCEG score recompute
  14. 2026-08-01 04:15 UTCEPSS rescore
  15. 2026-07-31 03:50 UTCEG score recompute
  16. 2026-07-30 16:27 UTCEPSS rescore
  17. 2026-07-30 03:02 UTCEG score recompute
  18. 2026-07-30 01:30 UTCEPSS rescore
  19. 2026-07-29 01:40 UTCEG score recompute
  20. 2026-07-28 15:36 UTCEPSS rescore
  21. 2026-07-27 18:05 UTCEG score recompute
  22. 2026-07-27 14:13 UTCEPSS rescore
  23. 2026-07-26 17:03 UTCEG score recompute
  24. 2026-07-26 14:54 UTCEPSS rescore
  25. 2026-07-26 14:54 UTCEPSS rescore
  26. 2026-07-25 14:17 UTCEPSS rescore
  27. 2026-07-24 14:17 UTCEPSS rescore
  28. 2026-07-23 14:18 UTCEPSS rescore
  29. 2026-07-23 03:05 UTCEG score recompute
  30. 2026-07-22 14:08 UTCEPSS rescore
  31. 2026-07-21 15:24 UTCEPSS rescore
  32. 2026-07-20 17:08 UTCEPSS rescore
  33. 2026-07-19 14:30 UTCEPSS rescore
  34. 2026-07-19 02:28 UTCEPSS rescore
  35. 2026-07-18 10:04 UTCEPSS rescore
  36. 2026-07-16 17:02 UTCEPSS rescore
  37. 2026-07-15 16:57 UTCEPSS rescore
  38. 2026-07-15 02:00 UTCEPSS rescore
  39. 2026-07-13 22:30 UTCEPSS rescore
  40. 2026-07-13 06:12 UTCEPSS rescore
  41. 2026-07-12 05:46 UTCEPSS rescore
  42. 2026-07-11 08:27 UTCEPSS rescore
  43. 2026-07-09 19:10 UTCEPSS rescore
  44. 2026-07-08 15:15 UTCEPSS rescore
  45. 2026-07-08 15:15 UTCEPSS rescore
  46. 2026-07-07 13:46 UTCEPSS rescore
  47. 2026-07-06 16:27 UTCEPSS rescore
  48. 2026-07-06 02:23 UTCEPSS rescore
  49. 2026-07-05 02:30 UTCEPSS rescore
  50. 2026-07-05 02:30 UTCEPSS rescore
  51. 2026-07-04 06:31 UTCEPSS rescore
  52. 2026-07-01 15:06 UTCEPSS rescore
  53. 2026-07-01 15:06 UTCEPSS rescore
  54. 2026-06-30 23:22 UTCEPSS rescore
  55. 2026-06-29 14:06 UTCEPSS rescore
  56. 2026-06-28 14:07 UTCEPSS rescore
  57. 2026-06-28 04:56 UTCEPSS rescore
  58. 2026-06-28 04:56 UTCEPSS rescore
  59. 2026-06-27 03:08 UTCEPSS rescore
  60. 2026-06-25 13:49 UTCEPSS rescore
  61. 2026-06-24 14:05 UTCEPSS rescore
  62. 2026-06-23 21:32 UTCEPSS rescore
  63. 2026-06-22 17:37 UTCNVD updateCVSS v4 → 5.5
  64. 2026-06-19 06:56 UTCEG score recompute
  65. 2026-06-19 06:56 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-12644?
CVE-2026-12644 is a medium vulnerability published on June 19, 2026. 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 —…
When was CVE-2026-12644 disclosed?
CVE-2026-12644 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12644 actively exploited?
CVE-2026-12644 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 59.0% of all scored CVEs.
What is the CVSS score of CVE-2026-12644?
CVE-2026-12644 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-12644?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12644, 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

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