CVE-2026-42488

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-06-18. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

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

Some shadow paging errors paths will switch the page-tables without updating the currently running vCPU reference. This causes a mismatch between the loaded page-tables and the mapcache metadata which can lead to corruption of the mapcache.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity81% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
29%
KEV
Not listed

Published

June 18, 2026

Last Modified

June 22, 2026

Advisory Details (3)

Auto-updated Jun 18, 2026
No patch confirmed yet.
generic

XSA-494 - Xen Security Advisories

http://xenbits.xen.org/xsa/advisory-494.html
generic

oss-security - Xen Security Advisory 494 v3 (CVE-2026-42488) - x86: mismatched mapcache metadata

http://www.openwall.com/lists/oss-security/2026/06/09/14
generic

XSA-494 - Xen Security Advisories

https://xenbits.xenproject.org/xsa/advisory-494.html

Vendor Advisories for CVE-2026-42488(1)

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

Affected Packages

(9 across 9 ecosystems)
Alpine:v3.20(1)
PackageVulnerable rangeFixed inDependents
xen—4.18.5-r9—
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
xen—4.19.5-r4—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
xen—4.20.3-r4—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
xen—4.20.3-r4—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
xen—4.21.1-r6—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
xen4.14.2+25-gb6a8c4f72d-2 ... 4.20.3+127-gc42374a105-1 (46 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
xen4.17.1+2-gb773c48e36-1 ... 4.20.3+127-gc42374a105-1 (25 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
xen4.20.0+68-g35cb38b222-1 ... 4.20.2+7-g1badcf5035-2 (6 versions)4.20.3+127-gc42374a105-0+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
xen4.20.0+68-g35cb38b222-1, 4.20.2+37-g61ff35323e-1, 4.20.2+7-g1badcf5035-1, 4.20.2+7-g1badcf5035-24.20.3+127-gc42374a105-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 57× 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.

Showing the most recent 100 of 217 total refreshes for this CVE.

  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 09:37 UTCEPSS rescore
  3. 2026-09-10 09:34 UTCEPSS rescore
  4. 2026-09-08 22:00 UTCEPSS rescore
  5. 2026-09-07 16:01 UTCEPSS rescore
  6. 2026-09-06 13:47 UTCEPSS rescore
  7. 2026-09-04 05:06 UTCEPSS rescore
  8. 2026-09-02 14:12 UTCEPSS rescore
  9. 2026-09-01 13:54 UTCEPSS rescore
  10. 2026-08-30 20:59 UTCEG score recompute
  11. 2026-08-30 20:59 UTCGHSA enrichment
  12. 2026-08-30 19:17 UTCEPSS rescore
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 21:41 UTCEPSS rescore
  15. 2026-08-27 14:25 UTCEPSS rescore
  16. 2026-08-26 14:46 UTCEPSS rescore
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-25 02:42 UTCGHSA enrichment
  19. 2026-08-24 15:03 UTCEG score recompute
  20. 2026-08-24 15:03 UTCGHSA enrichment
  21. 2026-08-24 00:28 UTCGHSA enrichment
  22. 2026-08-23 12:48 UTCGHSA enrichment
  23. 2026-08-23 01:11 UTCEG score recompute
  24. 2026-08-23 01:11 UTCGHSA enrichment
  25. 2026-08-23 00:19 UTCEPSS rescore
Show 75 more
  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-21 19:10 UTCGHSA enrichment
  3. 2026-08-21 07:22 UTCEG score recompute
  4. 2026-08-21 07:22 UTCGHSA enrichment
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-20 19:46 UTCGHSA enrichment
  7. 2026-08-20 08:09 UTCEG score recompute
  8. 2026-08-20 08:09 UTCGHSA enrichment
  9. 2026-08-19 17:03 UTCEPSS rescore
  10. 2026-08-19 07:43 UTCEG score recompute
  11. 2026-08-19 07:43 UTCGHSA enrichment
  12. 2026-08-18 13:48 UTCEPSS rescore
  13. 2026-08-17 13:47 UTCEPSS rescore
  14. 2026-08-17 08:39 UTCGHSA enrichment
  15. 2026-08-16 21:03 UTCEG score recompute
  16. 2026-08-16 21:03 UTCGHSA enrichment
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 09:26 UTCEG score recompute
  19. 2026-08-16 09:26 UTCGHSA enrichment
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-15 21:51 UTCGHSA enrichment
  22. 2026-08-15 10:14 UTCEG score recompute
  23. 2026-08-15 10:14 UTCGHSA enrichment
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-14 22:38 UTCGHSA enrichment
  26. 2026-08-14 11:02 UTCGHSA enrichment
  27. 2026-08-13 23:26 UTCEG score recompute
  28. 2026-08-13 23:26 UTCGHSA enrichment
  29. 2026-08-13 22:00 UTCEPSS rescore
  30. 2026-08-13 11:49 UTCGHSA enrichment
  31. 2026-08-13 00:07 UTCEG score recompute
  32. 2026-08-13 00:07 UTCGHSA enrichment
  33. 2026-08-12 13:51 UTCEPSS rescore
  34. 2026-08-12 12:31 UTCGHSA enrichment
  35. 2026-08-12 00:55 UTCEG score recompute
  36. 2026-08-12 00:55 UTCGHSA enrichment
  37. 2026-08-11 13:43 UTCEPSS rescore
  38. 2026-08-11 13:19 UTCGHSA enrichment
  39. 2026-08-11 01:44 UTCEG score recompute
  40. 2026-08-11 01:44 UTCGHSA enrichment
  41. 2026-08-11 00:00 UTCEPSS rescore
  42. 2026-08-10 14:07 UTCGHSA enrichment
  43. 2026-08-10 02:31 UTCGHSA enrichment
  44. 2026-08-09 14:56 UTCEG score recompute
  45. 2026-08-09 14:56 UTCGHSA enrichment
  46. 2026-08-09 13:46 UTCEPSS rescore
  47. 2026-08-09 03:20 UTCEG score recompute
  48. 2026-08-09 03:20 UTCGHSA enrichment
  49. 2026-08-08 16:37 UTCEPSS rescore
  50. 2026-08-08 15:44 UTCGHSA enrichment
  51. 2026-08-08 04:07 UTCGHSA enrichment
  52. 2026-08-07 16:31 UTCEG score recompute
  53. 2026-08-07 16:31 UTCGHSA enrichment
  54. 2026-08-07 04:55 UTCGHSA enrichment
  55. 2026-08-06 17:19 UTCEG score recompute
  56. 2026-08-06 17:19 UTCGHSA enrichment
  57. 2026-08-06 13:46 UTCEPSS rescore
  58. 2026-08-06 05:42 UTCEG score recompute
  59. 2026-08-06 05:42 UTCGHSA enrichment
  60. 2026-08-05 19:17 UTCEPSS rescore
  61. 2026-08-05 18:07 UTCGHSA enrichment
  62. 2026-08-05 02:59 UTCGHSA enrichment
  63. 2026-08-04 15:23 UTCEG score recompute
  64. 2026-08-04 15:23 UTCGHSA enrichment
  65. 2026-08-04 15:10 UTCEPSS rescore
  66. 2026-08-04 10:38 UTCEPSS rescore
  67. 2026-08-03 20:21 UTCEG score recompute
  68. 2026-08-03 20:21 UTCGHSA enrichment
  69. 2026-08-03 10:36 UTCEPSS rescore
  70. 2026-08-03 08:44 UTCGHSA enrichment
  71. 2026-08-02 20:20 UTCGHSA enrichment
  72. 2026-08-02 08:44 UTCEG score recompute
  73. 2026-08-02 08:44 UTCGHSA enrichment
  74. 2026-08-02 02:27 UTCEPSS rescore
  75. 2026-08-01 21:07 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-42488?
CVE-2026-42488 is a high vulnerability published on June 18, 2026. Some shadow paging errors paths will switch the page-tables without updating the currently running vCPU reference. This causes a mismatch between the loaded page-tables and the mapcache metadata which can lead to corruption of the mapcache.
When was CVE-2026-42488 disclosed?
CVE-2026-42488 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on June 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42488 actively exploited?
CVE-2026-42488 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 71.4% of all scored CVEs.
What is the CVSS score of CVE-2026-42488?
CVE-2026-42488 has a CVSS v3.1 base score of 8.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-42488?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42488, 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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