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 — 4 sources updated this week

Also known asEUVD-2026-50202 (ENISA EUVD) · GHSA-57gr-rx4p-h42m (GitHub Security Advisories)Source: ENISA EUVD

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: 0.3%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 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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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
22nd
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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 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 2026-10-27). 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 (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)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 Vulnrichment) · Technical impact total (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 29, 2026

Last Modified

October 19, 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(11)

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
—

Weakness Classification(1)

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

Additional Vendor Advisories

(9)

Data Freshness Timeline

(refreshed 10× in last 7d / 63× 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 339 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 239 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  7. 2026-10-27 19:51 UTCEG score recompute
  8. 2026-10-27 19:51 UTCVendor advisory
  9. 2026-10-27 19:51 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  10. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  11. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-25 14:12 UTCEG score recompute
  14. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  16. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  19. 2026-10-19 21:42 UTCEG score recompute
  20. 2026-10-19 21:42 UTCVendor advisory
  21. 2026-10-19 21:42 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-19 20:54 UTCEG score recompute
  23. 2026-10-19 20:54 UTCVendor advisory
  24. 2026-10-19 20:54 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  25. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
Show 75 more
  1. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-10-18 03:22 UTCEG score recompute
  3. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-16 17:36 UTCEG score recompute
  5. 2026-10-16 17:36 UTCVendor advisory
  6. 2026-10-16 17:35 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  8. 2026-10-16 16:10 UTCEG score recompute
  9. 2026-10-16 16:10 UTCVendor advisory
  10. 2026-10-16 16:09 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  11. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  12. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  13. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  14. 2026-10-13 11:39 UTCEG score recompute
  15. 2026-10-13 11:39 UTCVendor advisory
  16. 2026-10-13 11:39 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  18. 2026-10-12 15:47 UTCEG score recompute
  19. 2026-10-11 19:32 UTCEG score recompute
  20. 2026-10-11 16:47 UTCEG score recompute
  21. 2026-10-11 14:09 UTCEG score recompute
  22. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  23. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  24. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  25. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  26. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  27. 2026-10-07 00:02 UTCEG score recompute
  28. 2026-10-07 00:02 UTCVendor advisory
  29. 2026-10-07 00:02 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  30. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  31. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  32. 2026-10-05 02:39 UTCEG score recompute
  33. 2026-10-05 02:39 UTCVendor advisory
  34. 2026-10-05 02:39 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  35. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  36. 2026-10-04 07:05 UTCEG score recompute
  37. 2026-10-04 07:05 UTCVendor advisory
  38. 2026-10-04 07:05 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  39. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  40. 2026-10-02 17:58 UTCEG score recompute
  41. 2026-10-02 17:58 UTCVendor advisory
  42. 2026-10-02 17:58 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  44. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  45. 2026-10-01 15:48 UTCVendor advisory
  46. 2026-10-01 15:48 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  47. 2026-10-01 03:38 UTCEG score recompute
  48. 2026-10-01 03:38 UTCVendor advisory
  49. 2026-10-01 03:38 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  50. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  51. 2026-09-29 07:38 UTCEG score recompute
  52. 2026-09-29 07:38 UTCVendor advisory
  53. 2026-09-29 07:38 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  54. 2026-09-28 03:19 UTCEG score recompute
  55. 2026-09-28 03:19 UTCVendor advisory
  56. 2026-09-28 03:19 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  58. 2026-09-25 05:50 UTCEG score recompute
  59. 2026-09-25 05:50 UTCVendor advisory
  60. 2026-09-25 05:50 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  61. 2026-09-24 10:03 UTCVendor advisory
  62. 2026-09-24 10:03 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  63. 2026-09-23 21:52 UTCEG score recompute
  64. 2026-09-23 21:52 UTCVendor advisory
  65. 2026-09-23 21:52 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  66. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  67. 2026-09-23 04:12 UTCEG score recompute
  68. 2026-09-23 04:12 UTCVendor advisory
  69. 2026-09-23 04:12 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-09-22 15:52 UTCEG score recompute
  71. 2026-09-22 15:52 UTCVendor advisory
  72. 2026-09-22 15:52 UTCGHSA enrichmentGHSA-57gr-rx4p-h42m · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  74. 2026-09-20 00:24 UTCEG score recompute
  75. 2026-09-20 00:24 UTCVendor advisory

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 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…
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 October 19, 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 0.3% probability of exploitation in the next 30 days (22nd 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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