CVE-2018-12556

MEDIUMNVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

Score 5.9 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.9
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 2%CVSS: 5.9Exploit: NoneExposed: 0

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

The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which allows remote attackers to sign tampered yarn release packages with their own key.

CVSS v3
5.9
EG Score
5.9(medium)
EPSS
75.9%
KEV
Not listed

Published

May 16, 2019

Last Modified

November 21, 2024

References (12)

Weakness Classification(1)

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

Data Freshness Timeline

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2018-12556?
CVE-2018-12556 is a medium vulnerability published on May 16, 2019. The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which allows remote attackers to sign tampered yarn…
When was CVE-2018-12556 disclosed?
CVE-2018-12556 was first published in the National Vulnerability Database on May 16, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-12556 actively exploited?
CVE-2018-12556 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 75.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2018-12556?
CVE-2018-12556 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2018-12556?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-12556, 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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