CVE-2026-63898

HIGHNVD 7.87.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 0.2% (7th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 5 sources updated this week

Also known asEUVD-2026-45671 (ENISA EUVD) · GHSA-6rff-3vpp-qcmx (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

USB: serial: mct_u232: fix memory corruption with small endpoint

The driver overrides the maximum transfer size for a specific device which only accepts 16 byte packets for its 32 byte bulk-out endpoint.

Make sure to never increase the maximum transfer size to prevent slab corruption should a malicious device report a smaller endpoint max packet size than expected.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
7th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 19, 2026

Last Modified

October 30, 2026

Advisory Details (8)

Auto-updated Oct 30, 2026
Patch available.
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d8fdf33d6fcfb90cbec26299baf2352c84b2d768
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bd2ddb3fe9052ad8703593bbec26ecc7ca92869e
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/94edbbc5fe00d03cfe1d4e690d7d2cd36317a935
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/915b36d701950503c4ea0f6e314b10868e59fce3
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/90dbad14b109e5fdfb4934ff61e561d11ba3742d
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6cb48f8890f9b2051d7c34823057296a536a31c5
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57f332af1745014cd7e40414814ffaa6bc7d3b5b
Web page

USB: serial: mct_u232: fix memory corruption with small endpoint - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/39e295a91e80f3b91f61c7ada2bde434dcaba20d

Vendor Advisories for CVE-2026-63898(1)

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

Patch Availability(20)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-tools-oracle-edge (5.15.0.1114.120~20.04.1) @ focal2026-10-30ubuntu
ubuntulinux-tools-gcp-lts-22.04 (5.15.0.1118.115) @ jammy2026-10-30ubuntu
ubuntulinux-tools-ibm-edge (6.8.0-1066.67~22.04.1) @ jammy2026-10-30ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-10-30ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-10-30ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-10-30ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-10-30ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-10-30ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-30ubuntu
ubuntulinux-tools-azure-edge (7.0.0-1014.14~24.04.1) @ noble2026-10-30ubuntu
ubuntulinux-tools-oracle-edge (7.0.0-1011.11~24.04.1) @ noble2026-10-30ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1118.128~20.04.1) @ focal2026-10-30ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.15.0-1080 (5.15.0-1080.84) @ jammy2026-10-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-146.146) @ noble2026-10-30ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1070.78+fips1) @ noble2026-10-30ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1070.78) @ noble2026-10-30ubuntu
ubuntulinux-tools-nvidia-hwe-22.04-edge (6.8.0-1064.67~22.04.1) @ jammy2026-10-30ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1112.112) @ jammy2026-10-30ubuntu
ubuntulinux-tools-gcp-lts-24.04 (6.8.0-1070.78) @ noble2026-10-30ubuntu
linuxKernel @ 5.10.259 (fixes >=2.6.12)—osv

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)
  • every version up to 5.10.259-1: fixed in 5.10.259-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)
  • every version up to 6.1.176-1: fixed in 6.1.176-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)
  • every version up to 6.12.94-1: fixed in 6.12.94-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (142 versions)
  • every version up to 7.0.12-1: fixed in 7.0.12-1
—

Weakness Classification(1)

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

All Vendor Advisories

(19)

Data Freshness Timeline

(refreshed 14× in last 7d / 42× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 154 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 54 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  4. 2026-10-30 14:47 UTCEG score recomputeFirst assessed: 7.8 HIGH
  5. 2026-10-30 14:47 UTCVendor advisory
  6. 2026-10-30 14:47 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  7. 2026-10-30 14:46 UTCNVD updateCVSS v3 → 7.8 · severity → HIGH
  8. 2026-10-29 17:11 UTCEG score recompute
  9. 2026-10-29 17:11 UTCVendor advisory
  10. 2026-10-29 17:11 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  11. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  12. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  13. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  14. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  15. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  16. 2026-10-25 14:13 UTCEG score recompute
  17. 2026-10-25 00:55 UTCOSV refresh
  18. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  19. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  20. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  21. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  22. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  23. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  24. 2026-10-18 03:23 UTCEG score recompute
  25. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 12th percentile
Show 75 more
  1. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  2. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  3. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  4. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  5. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  6. 2026-10-12 15:48 UTCEG score recompute
  7. 2026-10-11 19:33 UTCEG score recompute
  8. 2026-10-11 16:48 UTCEG score recompute
  9. 2026-10-11 14:09 UTCEG score recompute
  10. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  11. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  15. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  16. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  17. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  21. 2026-10-01 08:55 UTCEG score recompute
  22. 2026-10-01 08:55 UTCVendor advisory
  23. 2026-10-01 08:55 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  24. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  25. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  26. 2026-09-28 07:32 UTCVendor advisory
  27. 2026-09-28 07:32 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  28. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  29. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  30. 2026-09-23 02:10 UTCVendor advisory
  31. 2026-09-23 02:10 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  32. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  33. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  34. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  35. 2026-09-16 13:07 UTCVendor advisory
  36. 2026-09-16 13:07 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  37. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  38. 2026-09-11 19:41 UTCVendor advisory
  39. 2026-09-11 19:41 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  40. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  41. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  42. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  43. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  44. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  45. 2026-09-05 20:11 UTCVendor advisory
  46. 2026-09-05 20:10 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  47. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  48. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  49. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  50. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  51. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  52. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  53. 2026-08-30 13:15 UTCVendor advisory
  54. 2026-08-30 13:15 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  55. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  56. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  57. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  58. 2026-08-27 11:55 UTCVendor advisory
  59. 2026-08-27 11:55 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  60. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  61. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  62. 2026-08-24 06:24 UTCVendor advisory
  63. 2026-08-24 06:24 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  64. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  65. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  66. 2026-08-21 05:03 UTCVendor advisory
  67. 2026-08-21 05:03 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  68. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  69. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  70. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  71. 2026-08-18 03:42 UTCVendor advisory
  72. 2026-08-18 03:42 UTCGHSA enrichmentGHSA-6rff-3vpp-qcmx
  73. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  74. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  75. 2026-08-15 01:53 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-63898?
CVE-2026-63898 is a high-severity vulnerability; its CVE record was published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: USB: serial: mct_u232: fix memory corruption with small endpoint The driver overrides the maximum transfer size for a specific device which only accepts 16 byte packets for its 32 byte bulk-out endpoint. Make sure to never increase…
When was the CVE record for CVE-2026-63898 published?
The CVE record for CVE-2026-63898 was published on July 19, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 30, 2026; the record at its source may have been updated since.
Is CVE-2026-63898 actively exploited?
CVE-2026-63898 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-63898?
CVE-2026-63898 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-63898?
A fix for CVE-2026-63898 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-63898 are linked in the Vendor Advisories panel on this page.

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