CVE-2018-3639

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.5 under NVD CVSS v3. EPSS exploit probability: 46.0%, top 2% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Weaponized
5.5
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 61%
CISA-KEV: Not listedEPSS: 61%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store Bypass (SSB), Variant 4.

CVSS v3
5.5
EG Score
5.5(medium)
EPSS
99.0%
KEV
Not listed

Published

May 22, 2018

Last Modified

May 29, 2026

References (294)

Vendor Advisories for CVE-2018-3639(20)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(26)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhvm-setup-plugins-0:4.3.0-1.el7ev2019-05-08redhat
redhatqemu-kvm-rhev-10:2.9.0-16.el7_4.182019-01-23redhat
redhatlibvirt-0:0.10.2-54.el6_7.92018-10-30redhat
redhatqemu-kvm-10:1.5.3-105.el7_2.182018-10-30redhat
redhatlibvirt-0:0.10.2-18.el6_4.182018-10-30redhat
redhatkernel-alt-0:4.14.0-115.el7a2018-10-30redhat
redhatqemu-kvm-2:0.12.1.2-2.355.el6_4.122018-10-30redhat
redhatqemu-kvm-2:0.12.1.2-2.448.el6_6.72018-10-30redhat
redhatlibvirt-0:0.10.2-46.el6_6.92018-10-30redhat
redhatlibvirt-0:1.2.17-13.el7_2.92018-10-30redhat
redhatlibvirt-0:0.10.2-29.el6_5.172018-10-30redhat
redhatlibvirt-0:2.0.0-10.el7_3.132018-10-30redhat
redhatqemu-kvm-2:0.12.1.2-2.479.el6_7.82018-10-30redhat
redhatqemu-kvm-2:0.12.1.2-2.415.el6_5.192018-10-30redhat
redhatkernel-0:2.6.32-358.91.4.el62018-08-14redhat
redhatkernel-0:3.10.0-693.37.4.el72018-08-14redhat
redhatkernel-rt-1:3.10.0-693.37.4.rt56.629.el6rt2018-08-14redhat
redhatqemu-kvm-rhev-10:2.10.0-21.el7_5.42018-08-07redhat
redhatrhvm-setup-plugins-0:4.2.10-1.el7ev2018-07-31redhat
redhatkernel-0:2.6.32-504.72.1.el62018-07-31redhat
redhatkernel-0:2.6.32-573.60.1.el62018-07-24redhat
redhatrhev-hypervisor7-0:7.3-20180710.1.el7ev2018-07-24redhat
redhatkernel-0:3.10.0-327.71.1.el72018-07-17redhat
redhatkernel-0:2.6.18-433.el52018-07-11redhat
redhatkernel-0:2.6.18-348.40.1.el52018-07-11redhat
redhatkernel-0:3.10.0-514.53.1.el72018-07-10redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

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

All Vendor Advisories

(25)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 3× in last 7d / 32× 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. 2026-07-11 08:24 UTCEPSS rescore
  2. 2026-07-09 19:06 UTCEPSS rescore
  3. 2026-07-05 02:27 UTCEPSS rescore
  4. 2026-07-04 08:26 UTCOSV refresh
  5. 2026-07-02 16:54 UTCEPSS rescore
  6. 2026-07-01 15:03 UTCEPSS rescore
  7. 2026-07-01 15:03 UTCEPSS rescore
  8. 2026-06-28 04:53 UTCEPSS rescore
  9. 2026-06-28 04:53 UTCEPSS rescore
  10. 2026-06-27 03:06 UTCEPSS rescore
  11. 2026-06-27 03:06 UTCEPSS rescore
  12. 2026-06-25 13:47 UTCEPSS rescore
  13. 2026-06-25 13:47 UTCEPSS rescore
  14. 2026-06-24 14:02 UTCEPSS rescore
  15. 2026-06-24 14:02 UTCEPSS rescore
  16. 2026-06-23 21:30 UTCEPSS rescore
  17. 2026-06-23 21:30 UTCEPSS rescore
  18. 2026-06-23 21:30 UTCEPSS rescore
  19. 2026-06-21 01:57 UTCEPSS rescore
  20. 2026-06-21 01:57 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
  24. 2026-06-17 17:50 UTCEPSS rescore
  25. 2026-06-16 17:50 UTCEPSS rescore
Show 34 more
  1. 2026-06-16 17:50 UTCEPSS rescore
  2. 2026-06-15 19:44 UTCOSV refresh
  3. 2026-06-15 17:45 UTCEPSS rescore
  4. 2026-06-14 23:15 UTCEPSS rescore
  5. 2026-06-14 23:14 UTCEPSS rescore
  6. 2026-06-12 23:09 UTCEPSS rescore
  7. 2026-06-12 23:09 UTCEPSS rescore
  8. 2026-06-11 13:57 UTCEPSS rescore
  9. 2026-06-10 22:16 UTCEPSS rescore
  10. 2026-06-10 13:19 UTCEPSS rescore
  11. 2026-06-06 13:45 UTCEPSS rescore
  12. 2026-06-06 13:45 UTCEPSS rescore
  13. 2026-06-05 22:45 UTCEPSS rescore
  14. 2026-06-05 22:45 UTCEPSS rescore
  15. 2026-06-05 06:08 UTCEPSS rescore
  16. 2026-06-05 06:08 UTCEPSS rescore
  17. 2026-06-04 13:10 UTCEPSS rescore
  18. 2026-06-02 20:11 UTCEPSS rescore
  19. 2026-06-02 20:11 UTCEPSS rescore
  20. 2026-06-01 13:50 UTCEPSS rescore
  21. 2026-06-01 13:50 UTCEPSS rescore
  22. 2026-05-31 22:29 UTCEPSS rescore
  23. 2026-05-31 00:14 UTCEPSS rescore
  24. 2026-05-31 00:14 UTCEPSS rescore
  25. 2026-05-29 13:41 UTCEPSS rescore
  26. 2026-05-28 13:42 UTCEPSS rescore
  27. 2026-05-28 13:42 UTCEPSS rescore
  28. 2026-05-28 07:57 UTCEG score recompute
  29. 2026-05-28 07:57 UTCVendor advisory
  30. 2026-05-27 13:38 UTCEPSS rescore
  31. 2026-05-27 13:38 UTCEPSS rescore
  32. 2026-05-26 07:17 UTCEPSS rescore
  33. 2026-05-26 07:17 UTCEPSS rescore
  34. 2026-05-24 23:43 UTCOSV refresh

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCmmxsrup/CVE-2018-3639
    First seen May 11, 2019

    Speculative Store Bypass (CVE-2018-3639) proof of concept for Linux

    Open source ↗
  • GitHub PoCtyhicks/ssbd-tools
    First seen May 31, 2018

    Tools to exercise the Linux kernel mitigation for CVE-2018-3639 (aka Variant 4) using the Speculative Store Bypass Disable (SSBD) feature of x86 processors

    Open source ↗
  • Exploit-DBEDB-44695✓ verified
    First seen May 22, 2018

    AMD / ARM / Intel - Speculative Execution Variant 4 Speculative Store Bypass

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2018-3639?
CVE-2018-3639 is a medium vulnerability published on May 22, 2018. Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store…
When was CVE-2018-3639 disclosed?
CVE-2018-3639 was first published in the National Vulnerability Database on May 22, 2018, with the most recent update on May 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-3639 actively exploited?
CVE-2018-3639 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2018-3639?
CVE-2018-3639 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2018-3639?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-3639, 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

Explore the affected products and dependency analysis for CVE-2018-3639

Explore →

Is Your Infrastructure Affected by CVE-2018-3639?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs