CVE-2026-63794

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. NVD baseline CVSS 7.8; sources differ by 0.0.

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

In the Linux kernel, the following vulnerability has been resolved:

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path

In sev_dbg_crypt(), the per-iteration transfer length is bounded by the source page offset (PAGE_SIZE - s_off) but not by the destination page offset (PAGE_SIZE - d_off). When d_off > s_off, the encrypt path (__sev_dbg_encrypt_user) performs a read-modify-write using a single-page intermediate buffer (dst_tpage):

  • __sev_dbg_decrypt() expands the size to round_up(len + (d_off & 15), 16)
before issuing the PSP command. If len + (d_off & 15) > PAGE_SIZE, the PSP writes beyond the end of the 4096-byte dst_tpage allocation.
  • The subsequent memcpy()/copy_from_user() into
page_address(dst_tpage) + (d_off & 15) of 'len' bytes overflows by up to 15 bytes under the same condition.

Trigger example: s_off = 0, d_off = 1, debug.len = PAGE_SIZE - the PSP is instructed to write round_up(4097, 16) = 4112 bytes to a 4096-byte buffer.

Fix by also bounding len by (PAGE_SIZE - d_off), the same check that sev_send_update_data() already performs for its single-page guest region.

================================================================== BUG: KASAN: slab-use-after-free in sev_dbg_crypt+0x993/0xd10 [kvm_amd] Write of size 4095 at addr ff110062293bb009 by task sev_dbg_test/228214

CPU: 96 UID: 0 PID: 228214 Comm: sev_dbg_test Tainted: G U W 7.0.0-smp--5ce9b0c48211-dbg #156 PREEMPTLAZY Tainted: [U]=USER, [W]=WARN Hardware name: Google Astoria/astoria, BIOS 0.20250817.1-0 08/25/2025 Call Trace: dump_stack_lvl+0x54/0x70 print_report+0xbc/0x260 kasan_report+0xa2/0xd0 kasan_check_range+0x25f/0x2c0 __asan_memcpy+0x40/0x70 sev_dbg_crypt+0x993/0xd10 [kvm_amd] sev_mem_enc_ioctl+0x33c/0x450 [kvm_amd] kvm_vm_ioctl+0x65d/0x6d0 [kvm] __se_sys_ioctl+0xb2/0x100 do_syscall_64+0xe8/0x870 entry_SYSCALL_64_after_hwframe+0x4b/0x53

The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x7fe72b6a0 pfn:0x62293bb memcg:ff11000112827d82 flags: 0x1400000000000000(node=1|zone=1) raw: 1400000000000000 0000000000000000 dead000000000122 0000000000000000 raw: 00000007fe72b6a0 0000000000000000 00000001ffffffff ff11000112827d82 page dumped because: kasan: bad access detected

Memory state around the buggy address: ff110062293bbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff110062293bbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ff110062293bc000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ff110062293bc080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ff110062293bc100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== Disabling lock debugging due to kernel taint

[sean: add sample KASAN splat, Fixes, and stable@]

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

July 19, 2026

Last Modified

August 17, 2026

Advisory Details (8)

Auto-updated Jul 30, 2026
No patch confirmed yet.
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f701ae476cb92a3a3d8844bb39bb63b4512684c8
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e1a0fe288dee07b7da25a71e007c1ecd1080315b
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9349b50f4b11f135fe73b56cb2c2c872d8bc71d7
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/889c2a9c59897ca912bf39df5bb92555a0a13df4
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/78ee2d50185a037b3d2452a97f3dad69c3f7f389
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/720949ed666f34ff28ffdfe1471a5861d1e41fdf
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/64f2449841ffc7d203183aa4c748c9c77951ecc5
generic

KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2753a097d1fe24c4351c608048612c74108aa89f

Vendor Advisories for CVE-2026-63794(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-31.31) @ resolute2026-09-11ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1013.13) @ resolute2026-09-11ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-09-11ubuntu

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

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (55 versions)5.10.262-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.176-1~deb11u1 (21 versions)6.1.177-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (54 versions)6.1.177-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (29 versions)6.12.95-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (156 versions)7.1.3-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

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 16× in last 7d / 113× 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 192 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-63794?
CVE-2026-63794 is a high vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Fix page overflow in sevdbgcrypt() for ENCRYPT path In sevdbgcrypt(), the per-iteration transfer length is bounded by the source page offset (PAGESIZE - soff) but not by the destination page offset (PAGESIZE - doff). When…
When was CVE-2026-63794 disclosed?
CVE-2026-63794 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63794 actively exploited?
CVE-2026-63794 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 96.2% of all scored CVEs.
What is the CVSS score of CVE-2026-63794?
CVE-2026-63794 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-63794?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63794, 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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