CVE-2026-34963

HIGHNVD 7.88.4▲
EchelonGraph scoreMEDIUM confidence

Score 8.4 from GitHub Security Advisory (severity: HIGH) published 2026-05-12. NVD baseline CVSS 7.8; sources differ by 0.6.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.4EG
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

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

barebox version prior to 2026.04.0 contains multiple memory-safety vulnerabilities in the EFI PE loader in efi/loader/pe.c where integer overflow in virtual image size computation using 32-bit arithmetic on section VirtualAddress and size values allows undersized heap allocation, and PE section loading logic fails to validate that PointerToRawData plus copied size remains within the PE file buffer. An attacker can supply a malicious EFI PE binary via TFTP, USB, SD card, or network boot to trigger heap buffer overflow or out-of-bounds read from heap memory, potentially achieving code execution in bootloader context.

CVSS v3
7.8
EG Score
8.4(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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
Severity84% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
5%
KEV
Not listed

Published

May 11, 2026

Last Modified

July 18, 2026

Advisory Details (3)

Auto-updated May 11, 2026
No patch confirmed yet.
generic

barebox EFI PE Loader Memory Safety Vulnerabilities | Advisories | VulnCheck

https://www.vulncheck.com/advisories/barebox-efi-pe-loader-memory-safety-vulnerabilities
generic

Release v2026.04.0 · barebox/barebox · GitHub

https://github.com/barebox/barebox/releases/tag/v2026.04.0
generic

GitHub - barebox/barebox: The barebox bootloader - Mirror of ssh://[email protected]/barebox · GitHub

https://github.com/barebox/barebox

Vendor Advisories for CVE-2026-34963(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 37× 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 133 total refreshes for this CVE.

  1. 2026-07-27 14:13 UTCEPSS rescore
  2. 2026-07-25 14:18 UTCEPSS rescore
  3. 2026-07-25 14:18 UTCEPSS rescore
  4. 2026-07-24 14:17 UTCEPSS rescore
  5. 2026-07-24 14:17 UTCEPSS rescore
  6. 2026-07-23 14:18 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 03:10 UTCEG score recompute
  9. 2026-07-22 14:08 UTCEPSS rescore
  10. 2026-07-21 15:24 UTCEPSS rescore
  11. 2026-07-20 17:08 UTCEPSS rescore
  12. 2026-07-19 14:31 UTCEPSS rescore
  13. 2026-07-19 02:29 UTCEPSS rescore
  14. 2026-07-18 10:04 UTCEPSS rescore
  15. 2026-07-18 04:02 UTCNVD updateCVSS v3 → 7.8
  16. 2026-07-16 17:03 UTCEPSS rescore
  17. 2026-07-16 02:49 UTCOSV refresh
  18. 2026-07-15 16:57 UTCEPSS rescore
  19. 2026-07-15 16:57 UTCEPSS rescore
  20. 2026-07-15 02:00 UTCEPSS rescore
  21. 2026-07-13 22:30 UTCEPSS rescore
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-13 06:13 UTCEPSS rescore
  24. 2026-07-12 05:46 UTCEPSS rescore
  25. 2026-07-11 08:27 UTCEPSS rescore
Show 75 more
  1. 2026-07-09 19:10 UTCEPSS rescore
  2. 2026-07-08 15:15 UTCEPSS rescore
  3. 2026-07-07 13:46 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-01 15:06 UTCEPSS rescore
  10. 2026-06-30 23:22 UTCEPSS rescore
  11. 2026-06-29 14:06 UTCEPSS rescore
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-28 14:07 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-28 04:56 UTCEPSS rescore
  16. 2026-06-28 04:56 UTCEPSS rescore
  17. 2026-06-28 02:56 UTCGHSA enrichment
  18. 2026-06-27 09:00 UTCGHSA enrichment
  19. 2026-06-27 03:08 UTCEPSS rescore
  20. 2026-06-26 20:59 UTCGHSA enrichment
  21. 2026-06-26 04:16 UTCGHSA enrichment
  22. 2026-06-25 13:49 UTCEPSS rescore
  23. 2026-06-25 13:49 UTCEPSS rescore
  24. 2026-06-24 14:05 UTCEPSS rescore
  25. 2026-06-23 21:33 UTCEPSS rescore
  26. 2026-06-23 21:33 UTCEPSS rescore
  27. 2026-06-22 14:25 UTCEPSS rescore
  28. 2026-06-22 14:25 UTCEPSS rescore
  29. 2026-06-21 01:59 UTCEPSS rescore
  30. 2026-06-19 19:25 UTCEPSS rescore
  31. 2026-06-19 19:25 UTCEPSS rescore
  32. 2026-06-18 17:52 UTCEPSS rescore
  33. 2026-06-18 17:52 UTCEPSS rescore
  34. 2026-06-17 17:53 UTCEPSS rescore
  35. 2026-06-17 00:46 UTCGHSA enrichment
  36. 2026-06-16 17:52 UTCEPSS rescore
  37. 2026-06-16 07:01 UTCGHSA enrichment
  38. 2026-06-15 17:49 UTCEPSS rescore
  39. 2026-06-15 01:31 UTCGHSA enrichment
  40. 2026-06-14 23:18 UTCEPSS rescore
  41. 2026-06-14 13:30 UTCGHSA enrichment
  42. 2026-06-14 01:19 UTCGHSA enrichment
  43. 2026-06-13 23:00 UTCEPSS rescore
  44. 2026-06-12 23:12 UTCEPSS rescore
  45. 2026-06-12 23:12 UTCEPSS rescore
  46. 2026-06-12 22:41 UTCGHSA enrichment
  47. 2026-06-12 10:39 UTCGHSA enrichment
  48. 2026-06-11 22:39 UTCGHSA enrichment
  49. 2026-06-11 14:00 UTCEPSS rescore
  50. 2026-06-11 10:38 UTCGHSA enrichment
  51. 2026-06-10 22:34 UTCGHSA enrichment
  52. 2026-06-10 22:18 UTCEPSS rescore
  53. 2026-06-10 13:22 UTCEPSS rescore
  54. 2026-06-10 10:32 UTCGHSA enrichment
  55. 2026-06-09 22:32 UTCGHSA enrichment
  56. 2026-06-09 08:22 UTCGHSA enrichment
  57. 2026-06-08 20:21 UTCGHSA enrichment
  58. 2026-06-08 14:17 UTCEPSS rescore
  59. 2026-06-08 14:17 UTCEPSS rescore
  60. 2026-06-08 07:02 UTCGHSA enrichment
  61. 2026-06-07 19:02 UTCGHSA enrichment
  62. 2026-06-07 07:01 UTCGHSA enrichment
  63. 2026-06-06 19:00 UTCGHSA enrichment
  64. 2026-06-06 13:47 UTCEPSS rescore
  65. 2026-06-06 13:47 UTCEPSS rescore
  66. 2026-06-06 06:59 UTCGHSA enrichment
  67. 2026-06-05 22:47 UTCEPSS rescore
  68. 2026-06-05 22:47 UTCEPSS rescore
  69. 2026-06-05 18:58 UTCGHSA enrichment
  70. 2026-06-05 06:56 UTCGHSA enrichment
  71. 2026-06-05 06:10 UTCEPSS rescore
  72. 2026-06-05 06:10 UTCEPSS rescore
  73. 2026-06-04 18:55 UTCGHSA enrichment
  74. 2026-06-04 13:12 UTCEPSS rescore
  75. 2026-06-04 13:12 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-34963?
CVE-2026-34963 is a high vulnerability published on May 11, 2026. barebox version prior to 2026.04.0 contains multiple memory-safety vulnerabilities in the EFI PE loader in efi/loader/pe.c where integer overflow in virtual image size computation using 32-bit arithmetic on section VirtualAddress and size values allows undersized heap allocation, and PE section…
When was CVE-2026-34963 disclosed?
CVE-2026-34963 was first published in the National Vulnerability Database on May 11, 2026, with the most recent update on July 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-34963 actively exploited?
CVE-2026-34963 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 94.8% of all scored CVEs.
What is the CVSS score of CVE-2026-34963?
CVE-2026-34963 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.4.
How do I remediate CVE-2026-34963?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-34963, 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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