CVE-2026-64336

MEDIUMNVD 5.55.5
EchelonGraph scoreMEDIUM confidence

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

Score 5.5 from GitHub Security Advisory published 2026-07-25. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
5.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

USB: serial: keyspan_pda: fix information leak

The write() callback is supposed to return the number of characters accepted or a negative errno. Since the addition of write fifo support the keyspan_pda implementation will however return the number characters submitted to the device if the write urb is not already in use. If this number is larger than the number of characters passed to write(), the line discipline continues writing data from beyond the tty write buffer.

Fix the information leak by making sure that keyspan_pda_write_start() returns zero on success as intended.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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 (value × EchelonGraph’s weight)
Severity55% × 45%
The EG Score, 5.5 of 10.
Exploitation0.1% × 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
0.1%
EPSS %ILE
1st
KEV
Not listed

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.

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 25, 2026

Last Modified

September 14, 2026

Advisory Details (8)

Auto-updated Sep 3, 2026
Patch available.
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e52ca411f50539ff1d0c877b9312771ca8a858c1
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e1494191a3aac665d3a2fce16169a97c346253ec
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d4b12b6b395e43a2b1d80be3745631fcaa9c047b
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cf6ca0aefae03958cfb5b189b0adbfb25c06bfac
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cccef1711efbcdbe999738ac27d37b9ef6271abd
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b069b7029862fafaff331d4c664d97d4ae828d6d
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6bfc8d01ac4068eced509f8fc74d0cd205e4dcec
Web page

USB: serial: keyspan_pda: fix information leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2f7a6b8ab3845bd1da02604f1a874b52a4555a72

Vendor Advisories for CVE-2026-64336(2)

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

Patch Availability(16)

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: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:11(1)
PackageVulnerable rangeFix by version rangeDependents
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:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (30 versions)
  • every version up to 6.12.96-1: fixed in 6.12.96-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (159 versions)
  • every version up to 7.1.4-1: fixed in 7.1.4-1
—

Weakness Classification(1)

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

All Vendor Advisories

(16)

Data Freshness Timeline

(refreshed 12× in last 7d / 61× 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 160 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 60 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  4. 2026-10-12 15:48 UTCEG score recompute
  5. 2026-10-11 19:32 UTCEG score recompute
  6. 2026-10-11 16:47 UTCEG score recompute
  7. 2026-10-11 14:09 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  11. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  13. 2026-10-07 06:13 UTCEG score recompute
  14. 2026-10-07 06:13 UTCVendor advisory
  15. 2026-10-07 06:13 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  17. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  19. 2026-10-04 07:35 UTCEG score recompute
  20. 2026-10-04 07:35 UTCVendor advisory
  21. 2026-10-04 07:34 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  22. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  23. 2026-10-02 19:31 UTCEG score recompute
  24. 2026-10-02 19:31 UTCVendor advisory
  25. 2026-10-02 19:31 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
Show 75 more
  1. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-10-01 04:18 UTCEG score recompute
  3. 2026-10-01 04:18 UTCVendor advisory
  4. 2026-10-01 04:17 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  5. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  6. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  7. 2026-09-28 04:18 UTCEG score recompute
  8. 2026-09-28 04:18 UTCVendor advisory
  9. 2026-09-28 04:17 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  10. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  11. 2026-09-25 09:50 UTCEG score recompute
  12. 2026-09-25 09:50 UTCVendor advisory
  13. 2026-09-25 09:50 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  14. 2026-09-23 22:10 UTCEG score recompute
  15. 2026-09-23 22:10 UTCVendor advisory
  16. 2026-09-23 22:10 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  17. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  18. 2026-09-22 22:05 UTCEG score recompute
  19. 2026-09-22 22:05 UTCVendor advisory
  20. 2026-09-22 22:04 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  21. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  22. 2026-09-20 01:30 UTCEG score recompute
  23. 2026-09-20 01:30 UTCVendor advisory
  24. 2026-09-20 01:30 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  25. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  26. 2026-09-18 09:46 UTCEG score recompute
  27. 2026-09-18 09:46 UTCVendor advisory
  28. 2026-09-18 09:46 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  29. 2026-09-17 09:12 UTCEG score recompute
  30. 2026-09-17 09:12 UTCVendor advisory
  31. 2026-09-17 09:12 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  32. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  33. 2026-09-16 06:32 UTCEG score recompute
  34. 2026-09-16 06:32 UTCVendor advisory
  35. 2026-09-16 06:32 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  36. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  37. 2026-09-14 12:34 UTCVendor advisory
  38. 2026-09-14 12:34 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  39. 2026-09-14 12:00 UTCEG score recompute
  40. 2026-09-14 12:00 UTCVendor advisory
  41. 2026-09-14 12:00 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  42. 2026-09-13 16:38 UTCVendor advisory
  43. 2026-09-13 16:38 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  44. 2026-09-12 16:34 UTCEG score recompute
  45. 2026-09-12 16:34 UTCVendor advisory
  46. 2026-09-12 16:34 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  47. 2026-09-11 16:27 UTCEG score recompute
  48. 2026-09-11 16:27 UTCVendor advisory
  49. 2026-09-11 16:27 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  50. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  51. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  52. 2026-09-10 13:27 UTCEG score recompute
  53. 2026-09-10 13:27 UTCVendor advisory
  54. 2026-09-10 13:27 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  55. 2026-09-09 08:38 UTCEG score recompute
  56. 2026-09-09 08:38 UTCVendor advisory
  57. 2026-09-09 08:38 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  58. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  59. 2026-09-07 21:17 UTCEG score recompute
  60. 2026-09-07 21:17 UTCVendor advisory
  61. 2026-09-07 21:17 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  62. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  63. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  64. 2026-09-05 19:21 UTCEG score recompute
  65. 2026-09-05 19:21 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  66. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  67. 2026-09-04 16:22 UTCEG score recompute
  68. 2026-09-04 16:22 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c · GitHub CVSS 5.5
  69. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  70. 2026-09-03 16:17 UTCEG score recomputeFirst assessed: 5.5 MEDIUM
  71. 2026-09-03 16:17 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c
  72. 2026-09-03 16:12 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  73. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  74. 2026-09-02 00:51 UTCGHSA enrichmentGHSA-mhg5-fr5x-3g7c
  75. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 7th percentile

Frequently asked(5)

What is CVE-2026-64336?
CVE-2026-64336 is a medium-severity vulnerability; its CVE record was published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: USB: serial: keyspan_pda: fix information leak The write() callback is supposed to return the number of characters accepted or a negative errno. Since the addition of write fifo support the keyspan_pda implementation will however…
When was the CVE record for CVE-2026-64336 published?
The CVE record for CVE-2026-64336 was published on July 25, 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 September 14, 2026; the record at its source may have been updated since.
Is CVE-2026-64336 actively exploited?
CVE-2026-64336 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64336?
CVE-2026-64336 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-64336?
A fix for CVE-2026-64336 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64336 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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