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NVD / CVE Program· CNA Linux

CVE-2026-23356: drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock()

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: 0.13% (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 7752569fc78e89794ce28946529850282233f99d, 933d161baa3794547adee621c0bf52cbf2c1b3cd, ab140365fb62c0bdab22b2f516aff563b2559e3b; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 7752569fc78e89794ce28946529850282233f99d, 933d161baa3794547adee621c0bf52cbf2c1b3cd, ab140365fb62c0bdab22b2f516aff563b2559e3b; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1; 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: drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock() Even though we check that we "should" be able to do lc_get_cumulative() while holding the device->al_lock spinlock, it may still fail, if some other code path decided to do lc_try_lock() with bad timing. If that happened, we logged "LOGIC BUG for enr=...", but still did not return an error. The rest of the code now assumed that this request has references for the relevant activity log extents. The implcations are that during an active resync, mutual exclusivity of resync versus application IO is not guaranteed. And a potential crash at this point may not realizs that these extents could have been target of in-flight IO and would need to be resynced just in case. Also, once the request completes, it will give up activity log references it does not even hold, which will trigger a BUG_ON(refcnt == 0) in lc_put(). Fix: Do not crash the kernel for a condition that is harmless during normal operation: also catch "e->refcnt == 0", not only "e == NULL" when being noisy about "al_complete_io() called on inactive extent %u\n". And do not try to be smart and "guess" whether something will work, then be surprised when it does not. Deal with the fact that it may or may not work. If it does not, remember a possible "partially in activity log" state (only possible for requests that cross extent boundaries), and return an error code from drbd_al_begin_io_nonblock(). A latter call for the same request will then resume from where we left off.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Mar 25, 2026
Updated
Oct 15, 2026
EPSS
0.1% · 3th 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%

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

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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 kernel3.10.1 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.167
  • linux linux kernel6.2 and later · before 6.6.130
  • linux linux kernel6.7 and later · before 6.12.77
  • linux linux kernel6.13 and later · before 6.18.17
  • linux linux kernel6.19 and later · before 6.19.7
  • linux linux kernel3.10
  • 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

    • 3.10affected
    • 6.19.7 and later · up to and including 6.19.*not affected · semver
    • 7.0 and laternot affected · original_commit_for_fix
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before 933d161baa3794547adee621c0bf52cbf2c1b3cdaffected · git
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before cf01aa6288e1190f89865e765056e2a9d8190639affected · git
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before 7752569fc78e89794ce28946529850282233f99daffected · git
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before e91d8d6565b7819d13dab21d4dbed5b45efba59baffected · git
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before eef1390125b660b8b61f9f227a03bb9c5e6d36a5affected · git
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before d1ef3aed4df2ef1fe46befd8f2da9a6ec5445508affected · git
    • 08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 and later · before f558e5404a72054b525dced1a0c66aa95a144153affected · git

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 6.19.8-16.19.8-1

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-2026-23353Mar 25, 2026 · ice: fix crash in ethtool offline loopback test
    22Monitor
  • ← EarlierCVE-2026-23355Mar 25, 2026 · ata: libata: cancel pending work after clearing deferred_qc
    22Monitor
  • Later →CVE-2026-23357Mar 25, 2026 · can: mcp251x: fix deadlock in error path of mcp251x_open
    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 Linux7752569fc78e89794ce28946529850282233f99dVendor (CNA)
Linux Linux933d161baa3794547adee621c0bf52cbf2c1b3cdVendor (CNA)
Linux Linuxab140365fb62c0bdab22b2f516aff563b2559e3bVendor (CNA)
Linux Linuxcf01aa6288e1190f89865e765056e2a9d8190639Vendor (CNA)
Linux Linuxd1ef3aed4df2ef1fe46befd8f2da9a6ec5445508Vendor (CNA)
Linux Linuxe91d8d6565b7819d13dab21d4dbed5b45efba59bVendor (CNA)
Linux Linuxeef1390125b660b8b61f9f227a03bb9c5e6d36a5Vendor (CNA)
Linux Linuxf558e5404a72054b525dced1a0c66aa95a144153Vendor (CNA)
azl3 kernel 6.6.126.1-1 on Azure Linux 3.06.6.130.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
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.

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-2026-3173937 days apartcrypto: tegra - Add missing CRYPTO_ALG_ASYNC
    35Monitor
  • CVE-2026-5295291 days apartiommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset
    35Monitor
  • CVE-2026-313989 days apartmm/rmap: fix incorrect pte restoration for lazyfree folios
    31Monitor
  • CVE-2026-4611764 days apartRDMA/mana: Remove user triggerable WARN_ON() in mana_ib_create_qp_rss()
    31Monitor
  • CVE-2025-39803191 days apartscsi: ufs: core: Remove WARN_ON_ONCE() call from ufshcd_uic_cmd_compl()
    31Monitor
  • CVE-2026-4602763 days apartnet/smc: avoid early lgr access in smc_clc_wait_msg
    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-617 · Reachable Assertion

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. Fix✗ → ✓

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

References

Show all references (8 more)

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

All records