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CVE-2026-31393· NVD / CVE Program· CNA Linux

Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.41% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 187e6fe939295be36063a1d91f8bebee04399a8c, 3b646516cba2ebc4b51a72954903326e7c1e443f, 5229e7d15771eac2b5886bfb1f976aea0c1eec14.

Low priority for now. Upgrade to Linux Linux 187e6fe939295be36063a1d91f8bebee04399a8c, 3b646516cba2ebc4b51a72954903326e7c1e443f, 5229e7d15771eac2b5886bfb1f976aea0c1eec14 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access l2cap_information_rsp() checks that cmd_len covers the fixed l2cap_info_rsp header (type + result, 4 bytes) but then reads rsp->data without verifying that the payload is present: - L2CAP_IT_FEAT_MASK calls get_unaligned_le32(rsp->data), which reads 4 bytes past the header (needs cmd_len >= 8). - L2CAP_IT_FIXED_CHAN reads rsp->data[0], 1 byte past the header (needs cmd_len >= 5). A truncated L2CAP_INFO_RSP with result == L2CAP_IR_SUCCESS triggers an out-of-bounds read of adjacent skb data. Guard each data access with the required payload length check. If the payload is too short, skip the read and let the state machine complete with safe defaults (feat_mask and remote_fixed_chan remain zero from kzalloc), so the info timer cleanup and l2cap_conn_start() still run and the connection is not stalled.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Apr 3, 2026
Updated
Oct 19, 2026
EPSS
0.4% · 35th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-31393

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel2.6.24 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.167
  • linux linux kernel6.2 and later · before 6.6.130
  • linux linux kernel6.7 and later · before 6.12.78
  • linux linux kernel6.13 and later · before 6.18.20
  • linux linux kernel6.19 and later · before 6.19.10
  • linux linux kernel7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.24affected
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before 187e6fe939295be36063a1d91f8bebee04399a8caffected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before 5229e7d15771eac2b5886bfb1f976aea0c1eec14affected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before 3b646516cba2ebc4b51a72954903326e7c1e443faffected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before 807bd1258453c4c83f6ae9dbc1e7b44860ff40d0affected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before 9aeacde4da0f02d42fd968fd32f245828b230171affected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before e7ff754e339e3d5ce29aa9f95352d0186df8fbd9affected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before db2872d054e467810078e2b9f440a5b326a601b2affected · git
    • 4e8402a3f884427f9233ba436459c158d1f2e114 and later · before dd815e6e3918dc75a49aaabac36e4f024d675101affected · git
    • before 2.6.24not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.10-16.19.10-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31391Apr 3, 2026 · crypto: atmel-sha204a - Fix OOM ->tfm_count leak
    22Monitor
  • ← EarlierCVE-2026-31392Apr 3, 2026 · smb: client: fix krb5 mount with username option
    32Monitor
  • Later →CVE-2026-31396Apr 3, 2026 · net: macb: fix use-after-free access to PTP clock
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux187e6fe939295be36063a1d91f8bebee04399a8cVendor (CNA)
Linux Linux3b646516cba2ebc4b51a72954903326e7c1e443fVendor (CNA)
Linux Linux5229e7d15771eac2b5886bfb1f976aea0c1eec14Vendor (CNA)
Linux Linux807bd1258453c4c83f6ae9dbc1e7b44860ff40d0Vendor (CNA)
Linux Linux9aeacde4da0f02d42fd968fd32f245828b230171Vendor (CNA)
Linux Linuxdb2872d054e467810078e2b9f440a5b326a601b2Vendor (CNA)
Linux Linuxdd815e6e3918dc75a49aaabac36e4f024d675101Vendor (CNA)
Linux Linuxe7ff754e339e3d5ce29aa9f95352d0186df8fbd9Vendor (CNA)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records