CVE-2026-3842

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-16. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in QEMU. This vulnerability allows a local attacker within a guest virtual machine to write data beyond its allocated memory. This occurs when cpu_physical_memory_map() returns a shorter length than expected, leading to an out-of-bounds write. Successful exploitation could result in unauthorized access to guest memory or corruption of heap-allocated objects, potentially causing information disclosure, data integrity issues, or a denial of service.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 16, 2026

Last Modified

August 24, 2026

Advisory Details (2)

Auto-updated Jul 16, 2026
Patch available. Sources: redhat.
redhat

2458150 – (CVE-2026-3842) CVE-2026-3842 qemu-kvm: hyperv/syndbg: missing mapped-length guard after cpu_physical_memory_map causes host OOB write

https://bugzilla.redhat.com/show_bug.cgi?id=2458150
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-3842

Vendor Advisories for CVE-2026-3842(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuqemu-utils (1:6.2+dfsg-2ubuntu6.30) @ jammy2026-08-30ubuntu

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.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
qemu1:10.0.0+ds-1 ... 1:9.2.2+ds-1~bpo12+1 (194 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
qemu1:10.0.2+ds-2 ... 1:10.0.8+ds-0+deb13u1 (12 versions)1:10.0.10+ds-0+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
qemu1:10.0.2+ds-2 ... 1:10.2.1+ds-1 (31 versions)1:10.2.2+ds-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 36× in last 7d / 170× 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 219 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-3842?
CVE-2026-3842 is a high vulnerability published on July 16, 2026. A flaw was found in QEMU. This vulnerability allows a local attacker within a guest virtual machine to write data beyond its allocated memory. This occurs when cpuphysicalmemory_map() returns a shorter length than expected, leading to an out-of-bounds write. Successful exploitation could result in…
When was CVE-2026-3842 disclosed?
CVE-2026-3842 was first published in the National Vulnerability Database on July 16, 2026, with the most recent update on August 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-3842 actively exploited?
CVE-2026-3842 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 93.8% of all scored CVEs.
What is the CVSS score of CVE-2026-3842?
CVE-2026-3842 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-3842?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-3842, 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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