CVE-2026-64557

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

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

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-29. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — Patch released this week
8.8EG
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: 0.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()

l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free.

Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks.

Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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)
Severity88% × 45%
The EG Score, 8.8 of 10.
Exploitation0.4% × 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
0.4%
EPSS %ILE
31st
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 29, 2026

Last Modified

August 17, 2026

Advisory Details (6)

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

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b39298044e5534612511a2ff5de03ba5f6e7a820
Web page

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8c37e4338c801ebb8cee52436c01c41e009f6e87
Web page

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/84e718b6a814edc84159361f9f454a4e92ae91ae
Web page

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/733e76e74e406c1d1ddc7369420dd8a47f48bb8a
Web page

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6fef032af0092ed5ccb767239a9ac1bc38c08a40
Web page

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/36da806f7fbaee56ad9e81859deec203f9728700

Patch Availability(5)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatkernel-0:5.14.0-687.55.1.el9_82026-10-08redhat
ubuntulinux-tools-azure-lts-26.04 (7.0.0-1017.17) @ resolute2026-10-07ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1015.15) @ resolute2026-10-07ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-38.38) @ resolute2026-10-07ubuntu
ubuntulinux-tools-nvidia-tegra-rt-6.8 (6.8.0-1035.38) @ noble2026-10-07ubuntu

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 ... 7.2~rc5-1~exp1 (500 versions)
  • every version on: no fix on record
—
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
—

Additional Vendor Advisories

(4)

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 14× in last 7d / 84× 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 302 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 202 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  2. 2026-10-13 11:39 UTCEG score recompute
  3. 2026-10-13 11:39 UTCVendor advisory
  4. 2026-10-13 11:39 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  5. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  6. 2026-10-12 15:47 UTCEG score recompute
  7. 2026-10-11 19:32 UTCEG score recompute
  8. 2026-10-11 16:47 UTCEG score recompute
  9. 2026-10-11 14:09 UTCEG score recompute
  10. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  11. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  15. 2026-10-07 00:02 UTCEG score recompute
  16. 2026-10-07 00:02 UTCVendor advisory
  17. 2026-10-07 00:02 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  18. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  19. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-10-05 02:39 UTCEG score recompute
  21. 2026-10-05 02:39 UTCVendor advisory
  22. 2026-10-05 02:39 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  23. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  24. 2026-10-04 07:05 UTCEG score recompute
  25. 2026-10-04 07:05 UTCVendor advisory
Show 75 more
  1. 2026-10-04 07:05 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  2. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  3. 2026-10-02 17:58 UTCEG score recompute
  4. 2026-10-02 17:58 UTCVendor advisory
  5. 2026-10-02 17:58 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  6. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  7. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  8. 2026-10-01 15:48 UTCVendor advisory
  9. 2026-10-01 15:48 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  10. 2026-10-01 03:38 UTCEG score recompute
  11. 2026-10-01 03:38 UTCVendor advisory
  12. 2026-10-01 03:38 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  13. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-09-29 07:38 UTCEG score recompute
  15. 2026-09-29 07:38 UTCVendor advisory
  16. 2026-09-29 07:38 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-09-28 03:19 UTCEG score recompute
  18. 2026-09-28 03:19 UTCVendor advisory
  19. 2026-09-28 03:19 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  20. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  21. 2026-09-25 05:50 UTCEG score recompute
  22. 2026-09-25 05:50 UTCVendor advisory
  23. 2026-09-25 05:50 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  24. 2026-09-24 10:03 UTCVendor advisory
  25. 2026-09-24 10:03 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  26. 2026-09-23 21:52 UTCEG score recompute
  27. 2026-09-23 21:52 UTCVendor advisory
  28. 2026-09-23 21:52 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  29. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  30. 2026-09-23 04:12 UTCEG score recompute
  31. 2026-09-23 04:12 UTCVendor advisory
  32. 2026-09-23 04:12 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  33. 2026-09-22 15:52 UTCEG score recompute
  34. 2026-09-22 15:52 UTCVendor advisory
  35. 2026-09-22 15:52 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  36. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  37. 2026-09-20 00:24 UTCEG score recompute
  38. 2026-09-20 00:24 UTCVendor advisory
  39. 2026-09-20 00:24 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  40. 2026-09-19 05:00 UTCEG score recompute
  41. 2026-09-19 05:00 UTCVendor advisory
  42. 2026-09-19 05:00 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  44. 2026-09-18 15:20 UTCVendor advisory
  45. 2026-09-18 15:20 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  46. 2026-09-18 01:47 UTCEG score recompute
  47. 2026-09-18 01:47 UTCVendor advisory
  48. 2026-09-18 01:47 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  49. 2026-09-17 01:37 UTCEG score recompute
  50. 2026-09-17 01:37 UTCVendor advisory
  51. 2026-09-17 01:37 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  52. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  53. 2026-09-16 05:50 UTCEG score recompute
  54. 2026-09-16 05:50 UTCVendor advisory
  55. 2026-09-16 05:50 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  56. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  57. 2026-09-15 08:18 UTCEG score recompute
  58. 2026-09-15 08:18 UTCVendor advisory
  59. 2026-09-15 08:18 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  60. 2026-09-14 09:24 UTCVendor advisory
  61. 2026-09-14 09:24 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  62. 2026-09-13 21:13 UTCEG score recompute
  63. 2026-09-13 21:13 UTCVendor advisory
  64. 2026-09-13 21:13 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  65. 2026-09-13 09:02 UTCVendor advisory
  66. 2026-09-13 09:01 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  67. 2026-09-12 20:51 UTCEG score recompute
  68. 2026-09-12 20:51 UTCVendor advisory
  69. 2026-09-12 20:51 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-09-12 08:37 UTCVendor advisory
  71. 2026-09-12 08:37 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  72. 2026-09-11 20:25 UTCEG score recompute
  73. 2026-09-11 20:25 UTCVendor advisory
  74. 2026-09-11 20:25 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  75. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile

Frequently asked(5)

What is CVE-2026-64557?
CVE-2026-64557 is a high-severity vulnerability; its CVE record was published on July 29, 2026. In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2capsocknewconnectioncb() l2capsocknewconnectioncb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable…
When was the CVE record for CVE-2026-64557 published?
The CVE record for CVE-2026-64557 was published on July 29, 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 August 17, 2026; the record at its source may have been updated since.
Is CVE-2026-64557 actively exploited?
CVE-2026-64557 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64557?
CVE-2026-64557 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64557?
A fix for CVE-2026-64557 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64557 are linked in the Vendor Advisories panel on this page.

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