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NVD / CVE Program· CNA Linux

CVE-2026-31498: Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 042e2cd4bb11e5313b19b87593616524949e4c52, 25f420a0d4cfd61d3d23ec4b9c56d9f443d91377, 4.10; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 042e2cd4bb11e5313b19b87593616524949e4c52, 25f420a0d4cfd61d3d23ec4b9c56d9f443d91377, 4.10; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes 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: Fix ERTM re-init and zero pdu_len infinite loop l2cap_config_req() processes CONFIG_REQ for channels in BT_CONNECTED state to support L2CAP reconfiguration (e.g. MTU changes). However, since both CONF_INPUT_DONE and CONF_OUTPUT_DONE are already set from the initial configuration, the reconfiguration path falls through to l2cap_ertm_init(), which re-initializes tx_q, srej_q, srej_list, and retrans_list without freeing the previous allocations and sets chan->sdu to NULL without freeing the existing skb. This leaks all previously allocated ERTM resources. Additionally, l2cap_parse_conf_req() does not validate the minimum value of remote_mps derived from the RFC max_pdu_size option. A zero value propagates to l2cap_segment_sdu() where pdu_len becomes zero, causing the while loop to never terminate since len is never decremented, exhausting all available memory. Fix the double-init by skipping l2cap_ertm_init() and l2cap_chan_ready() when the channel is already in BT_CONNECTED state, while still allowing the reconfiguration parameters to be updated through l2cap_parse_conf_req(). Also add a pdu_len zero check in l2cap_segment_sdu() as a safeguard.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 22, 2026
Updated
Nov 5, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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.

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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 kernel4.4.238 and later · before 4.5
  • linux linux kernel4.9.238 and later · before 4.10
  • linux linux kernel4.14.200 and later · before 4.15
  • linux linux kernel4.19.149 and later · before 4.20
  • linux linux kernel5.4.69 and later · before 5.5
  • linux linux kernel5.7.1 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.168
  • linux linux kernel6.2 and later · before 6.6.131
  • linux linux kernel6.7 and later · before 6.12.80
  • linux linux kernel6.13 and later · before 6.18.21
  • linux linux kernel6.19 and later · before 6.19.11
  • linux linux kernel5.7
  • 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

    • 4ad03ff6f680681c5f78254e37c4c856fa953629, b7d0ca715c1008acd2fc018f02a56fed88f78b75, 799263eb37a4f7f6d39334046929c3bc92452a7f, 8828622fb9b4201eeb0870587052e3d834cfaf61, b432ea85ab8472763870dd0f2c186130dd36d68c, 5.7affected
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before 9760b83cfd24b38caee663f429011a0dd6064fa9affected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before de37e2655b7abc3f59254c6b72256840f39fc6d5affected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before e7aab23b7df89a3d754a5f0a7d2237548b328bd0affected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before 52667c859fe33f70c2e711cb81bbd505d5eb8e75affected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before 9a21a631ee034b1573dce14b572a24943dbfd7aeaffected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before 900e4db5385ec2cacd372345a80ab9c8e105b3a3affected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before 042e2cd4bb11e5313b19b87593616524949e4c52affected · git
    • 96298f640104e4cd9a913a6e50b0b981829b94ff and later · before 25f420a0d4cfd61d3d23ec4b9c56d9f443d91377affected · git
    • 4.4.238 and later · before 4.5affected · 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 6.19.11-16.19.11-1
SUSE:Linux Enterprise Live Patching 12 SP5kernel-defaultbefore 4.12.14-122.317.14.12.14-122.317.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_84before 1-8.7.11-8.7.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7_Update_19before 1-150700.15.3.41-150700.15.3.4
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7-RT_Update_18before 1-150700.1.5.11-150700.1.5.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-64kbbefore 6.4.0-150700.53.73.26.4.0-150700.53.73.2
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-defaultbefore 6.4.0-150700.53.73.26.4.0-150700.53.73.2
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-default-basebefore 6.4.0-150700.53.73.2.150700.17.41.46.4.0-150700.53.73.2.150700.17.41.4
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-sourcebefore 6.4.0-150700.53.73.16.4.0-150700.53.73.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-zfcpdumpbefore 6.4.0-150700.53.73.26.4.0-150700.53.73.2
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-docsbefore 6.4.0-150700.53.73.16.4.0-150700.53.73.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-obs-buildbefore 6.4.0-150700.53.73.26.4.0-150700.53.73.2
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-symsbefore 6.4.0-150700.53.73.16.4.0-150700.53.73.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP7kernel-azurebefore 6.4.0-150700.53.73.26.4.0-150700.53.73.2
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-sourcebefore 4.12.14-122.317.14.12.14-122.317.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-symsbefore 4.12.14-122.317.14.12.14-122.317.1
SUSE:Real Time Module 15 SP7kernel-rtbefore 6.4.0-150700.7.67.16.4.0-150700.7.67.1
SUSE:Real Time Module 15 SP7kernel-source-rtbefore 6.4.0-150700.7.67.16.4.0-150700.7.67.1
SUSE:Real Time Module 15 SP7kernel-syms-rtbefore 6.4.0-150700.7.67.16.4.0-150700.7.67.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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

Published before and after this one in the same product

  • ← EarlierCVE-2026-31496Apr 22, 2026 · netfilter: nf_conntrack_expect: skip expectations in other netns via proc
    22Monitor
  • ← EarlierCVE-2026-31497Apr 22, 2026 · Bluetooth: btusb: clamp SCO altsetting table indices
    22Monitor
  • Later →CVE-2026-31499Apr 22, 2026 · Bluetooth: L2CAP: Fix deadlock in l2cap_conn_del()
    22Monitor

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 Linux042e2cd4bb11e5313b19b87593616524949e4c52Vendor (CNA)
Linux Linux25f420a0d4cfd61d3d23ec4b9c56d9f443d91377Vendor (CNA)
Linux Linux4.10Vendor (CNA)
Linux Linux4.15Vendor (CNA)
Linux Linux4.20Vendor (CNA)
Linux Linux4.5Vendor (CNA)
Linux Linux5.5Vendor (CNA)
Linux Linux52667c859fe33f70c2e711cb81bbd505d5eb8e75Vendor (CNA)
Linux Linux900e4db5385ec2cacd372345a80ab9c8e105b3a3Vendor (CNA)
Linux Linux9760b83cfd24b38caee663f429011a0dd6064fa9Vendor (CNA)
Linux Linux9a21a631ee034b1573dce14b572a24943dbfd7aeVendor (CNA)
Linux Linuxde37e2655b7abc3f59254c6b72256840f39fc6d5Vendor (CNA)
Linux Linuxe7aab23b7df89a3d754a5f0a7d2237548b328bd0Vendor (CNA)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
suse:kernel-64kb6.4.0-150700.53.73.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-default4.12.14-122.317.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package registry (OSV)
suse:kernel-default-base6.4.0-150700.53.73.2.150700.17.41.4 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kernel-docs6.4.0-150700.53.73.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7-RT_Update_181-150700.1.5.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-rt6.4.0-150700.7.67.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-source4.12.14-122.317.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kernel-source-rt6.4.0-150700.7.67.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-syms4.12.14-122.317.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kernel-syms-rt6.4.0-150700.7.67.1 · SUSE:Real Time Module 15 SP7Package registry (OSV)
suse:kernel-zfcpdump6.4.0-150700.53.73.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:kgraft-patch-SLE12-SP5_Update_841-8.7.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package 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.

No history yet (it accumulates with the daily EPSS job).

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.

  • CVE-2026-314480 days apartext4: avoid infinite loops caused by residual data
    37Monitor
  • CVE-2026-6388988 days apartscsi: scsi_transport_fc: Widen FPIN pname walker counter to u32
    32Monitor
  • CVE-2026-5293363 days apartio_uring/poll: fix signed comparison in io_poll_get_ownership()
    31Monitor
  • CVE-2026-315522 days apartwifi: wlcore: Return -ENOMEM instead of -EAGAIN if there is not enough headroom
    30Monitor
  • CVE-2026-2345119 days apartbonding: prevent potential infinite loop in bond_header_parse()
    30Monitor
  • CVE-2026-4605235 days apartceph: only d_add() negative dentries when they are unhashed
    30Monitor

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 with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')

CVSS vector

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

nvd-primary

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

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