CVE-2026-64540

HIGHPre-NVD 8.18.1
EchelonGraph scoreMEDIUM confidence

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

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-07-27. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week
8.1EG
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: 0.3%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup()

genelink_rx_fixup() splits an aggregated RX frame into its individual packets, using a per-packet length taken from device-supplied data. That length is only bounded by GL_MAX_PACKET_LEN (1514); it is never compared against how many bytes were actually received.

A malicious GeneLink (GL620A) device can therefore send a short URB whose header claims packet_count > 1 and a first packet of up to 1514 bytes.

skb_put_data(gl_skb, packet->packet_data, size);

then copies past the end of the receive buffer and hands the adjacent slab contents up the network stack, an out-of-bounds read that leaks kernel heap. No privilege is required: the path runs in the usbnet RX softirq as soon as the interface is up.

BUG: KASAN: slab-out-of-bounds in genelink_rx_fixup (drivers/net/usb/gl620a.c:112) Read of size 1514 at addr ffff888011309708 by task ksoftirqd/0/14 Call Trace: ... __asan_memcpy (mm/kasan/shadow.c:105) genelink_rx_fixup (include/linux/skbuff.h:2814 drivers/net/usb/gl620a.c:112) usbnet_bh (drivers/net/usb/usbnet.c:572 drivers/net/usb/usbnet.c:1589) process_one_work (kernel/workqueue.c:3322) bh_worker (kernel/workqueue.c:3405) tasklet_action (kernel/softirq.c:965) handle_softirqs (kernel/softirq.c:622) run_ksoftirqd (kernel/softirq.c:1076) ...

skb_pull() already verifies that the requested length fits the buffer and returns NULL otherwise. Move it ahead of the copy and check its result, so a packet that overruns the received data is rejected before it is read. Well-formed frames, whose packets are fully present, are unaffected.

CVSS v3
8.1
EG Score
8.1HIGHmedium confidence
EG Risk
37
EG Risk 37/100

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)
Severity81% × 45%
Impact severity (EG Severity): CVSS 8.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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
0.3%
EPSS %ILE
18th
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 (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.

EG Severity
8.1 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-19). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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 27, 2026

Last Modified

October 19, 2026

Advisory Details (8)

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

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8624e179fa3ce23c2fbd1a198ce30764b73f054a
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/573418f7ea8f859a841417eb4b915594094fd967
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4359376e6238d89977a35086e47ca3b07f43e850
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3ef79fa3860e644c8de7834fa7300e1c58f38862
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/255d03551f94c7bdd86c7d9181a70b21917d829f
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db
Web page

usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0575599e451aff3c5329922562374a2cab25fc51

Vendor Advisories for CVE-2026-64540(1)

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

Patch Availability(15)

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

(6 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (55 versions)
  • every version up to 5.10.262-1: fixed in 5.10.262-1
—
linux-6.16.1.106-3~deb11u1 ... 6.1.177-1~deb11u1 (22 versions)
  • every version up to 6.1.180-1~deb11u1: fixed in 6.1.180-1~deb11u1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)
  • every version up to 6.1.180-1: fixed in 6.1.180-1
—
linux-6.12—
  • every version up to 6.12.100-1~deb12u1: fixed in 6.12.100-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.96-1 (31 versions)
  • every version up to 6.12.100-1: fixed in 6.12.100-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (160 versions)
  • every version up to 7.1.5-1: fixed in 7.1.5-1
—

Weakness Classification(1)

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

All Vendor Advisories

(15)

Data Freshness Timeline

(refreshed 22× in last 7d / 65× 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 99 of 253 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 154 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 21:42 UTCEG score recompute
  2. 2026-10-19 21:42 UTCVendor advisory
  3. 2026-10-19 21:42 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  4. 2026-10-19 20:55 UTCEG score recompute
  5. 2026-10-19 20:55 UTCVendor advisory
  6. 2026-10-19 20:54 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  7. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  8. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  9. 2026-10-18 03:22 UTCEG score recompute
  10. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  11. 2026-10-16 17:36 UTCEG score recompute
  12. 2026-10-16 17:36 UTCVendor advisory
  13. 2026-10-16 17:35 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  14. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  15. 2026-10-16 16:10 UTCEG score recompute
  16. 2026-10-16 16:10 UTCVendor advisory
  17. 2026-10-16 16:09 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  18. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  19. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  20. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  21. 2026-10-13 11:39 UTCEG score recompute
  22. 2026-10-13 11:39 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  23. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  24. 2026-10-12 15:47 UTCEG score recompute
  25. 2026-10-11 19:32 UTCEG score recompute
Show 74 more
  1. 2026-10-11 16:47 UTCEG score recompute
  2. 2026-10-11 14:09 UTCEG score recompute
  3. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  4. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  5. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  6. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  7. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  8. 2026-10-07 01:30 UTCEG score recompute
  9. 2026-10-07 01:30 UTCVendor advisory
  10. 2026-10-07 01:30 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  11. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  12. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  13. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  14. 2026-10-04 07:17 UTCEG score recompute
  15. 2026-10-04 07:17 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  16. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  17. 2026-10-02 18:27 UTCEG score recompute
  18. 2026-10-02 18:27 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  21. 2026-10-01 15:52 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  22. 2026-10-01 03:51 UTCEG score recompute
  23. 2026-10-01 03:51 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  24. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  25. 2026-09-29 07:52 UTCEG score recompute
  26. 2026-09-29 07:52 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  27. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  28. 2026-09-28 03:32 UTCEG score recompute
  29. 2026-09-28 03:32 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  30. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  31. 2026-09-25 06:50 UTCEG score recompute
  32. 2026-09-25 06:50 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  33. 2026-09-24 10:03 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  34. 2026-09-23 22:02 UTCEG score recompute
  35. 2026-09-23 22:02 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  36. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  37. 2026-09-23 09:48 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  38. 2026-09-22 21:48 UTCEG score recompute
  39. 2026-09-22 21:48 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  40. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  41. 2026-09-20 00:55 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  42. 2026-09-19 08:12 UTCEG score recompute
  43. 2026-09-19 08:12 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  44. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  45. 2026-09-18 18:53 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  46. 2026-09-18 02:15 UTCEG score recompute
  47. 2026-09-18 02:15 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  48. 2026-09-17 01:46 UTCEG score recompute
  49. 2026-09-17 01:46 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  50. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  51. 2026-09-16 06:16 UTCEG score recompute
  52. 2026-09-16 06:16 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  53. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  54. 2026-09-15 09:06 UTCEG score recompute
  55. 2026-09-15 09:06 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  56. 2026-09-14 09:12 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  57. 2026-09-13 21:12 UTCEG score recompute
  58. 2026-09-13 21:12 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  59. 2026-09-13 09:06 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  60. 2026-09-12 21:06 UTCEG score recompute
  61. 2026-09-12 21:06 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  62. 2026-09-12 09:04 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  63. 2026-09-11 20:53 UTCEG score recompute
  64. 2026-09-11 20:53 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  65. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  66. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  67. 2026-09-11 08:49 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  68. 2026-09-10 20:47 UTCEG score recompute
  69. 2026-09-10 20:47 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  70. 2026-09-10 08:09 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  71. 2026-09-09 08:17 UTCEG score recompute
  72. 2026-09-09 08:17 UTCGHSA enrichmentGHSA-rwwq-q965-ghfj · GitHub severity HIGH · GitHub CVSS 8.1
  73. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  74. 2026-09-07 21:02 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-64540?
CVE-2026-64540 is a high-severity vulnerability; its CVE record was published on July 27, 2026. In the Linux kernel, the following vulnerability has been resolved: usbnet: gl620a: fix out-of-bounds read in genelinkrxfixup() genelinkrxfixup() splits an aggregated RX frame into its individual packets, using a per-packet length taken from device-supplied data. That length is only bounded by…
When was the CVE record for CVE-2026-64540 published?
The CVE record for CVE-2026-64540 was published on July 27, 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 19, 2026; the record at its source may have been updated since.
Is CVE-2026-64540 actively exploited?
CVE-2026-64540 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64540?
CVE-2026-64540 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64540?
A fix for CVE-2026-64540 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64540 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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