NVD / CVE Program· CNA Linux

CVE-2025-71269: btrfs: do not free data reservation in fallback from inline due to -ENOSPC

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: 0.22% (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.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: Linux Linux 0a1fbbd780f04d1b6cf48dd327c866ba937de1c4, 3a9fd45afadec1fbfec72057b9473d509fa8b68c, 3edd1f6c7c520536b62b2904807033597554dbac; azl3 kernel 6.6.130.1-3 on Azure Linux 3.0 6.6.134.1-2.
Severity is disputed: the assigning authority (CNA) scores it 7.5, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 0a1fbbd780f04d1b6cf48dd327c866ba937de1c4, 3a9fd45afadec1fbfec72057b9473d509fa8b68c, 3edd1f6c7c520536b62b2904807033597554dbac; azl3 kernel 6.6.130.1-3 on Azure Linux 3.0 6.6.134.1-2 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: btrfs: do not free data reservation in fallback from inline due to -ENOSPC If we fail to create an inline extent due to -ENOSPC, we will attempt to go through the normal COW path, reserve an extent, create an ordered extent, etc. However we were always freeing the reserved qgroup data, which is wrong since we will use data. Fix this by freeing the reserved qgroup data in __cow_file_range_inline() only if we are not doing the fallback (ret is <= 0).

MediumCVSS 5.5 · v3.1—No exploit Fix available

Published: Mar 18, 2026
Updated: Oct 19, 2026
EPSS: 0.2% · 13th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 5.5
CNA · Linux: 7.5; 2.0 point gap

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

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.

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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_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 and later · before 6.1.168
linux linux kernel6.2 and later · before 6.6.134
linux linux kernel6.7 and later · before 6.12.81
linux linux kernel6.13 and later · before 6.18.10
linux linux kernel6.19

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
- 4.4affected
- 94ed938aba557aa798acf496f09afb289b619fcd and later · before 3edd1f6c7c520536b62b2904807033597554dbacaffected · git
- 94ed938aba557aa798acf496f09afb289b619fcd and later · before 3a9fd45afadec1fbfec72057b9473d509fa8b68caffected · git
- 94ed938aba557aa798acf496f09afb289b619fcd and later · before 0a1fbbd780f04d1b6cf48dd327c866ba937de1c4affected · git
- 94ed938aba557aa798acf496f09afb289b619fcd and later · before 6de3a371a8b9fd095198b1aa68c22cc10a4c6961affected · git
- 94ed938aba557aa798acf496f09afb289b619fcd and later · before f8da41de0bff9eb1d774a7253da0c9f637c4470aaffected · git
- before 4.4not affected · semver
- 6.1.168 and later · up to and including 6.1.*not affected · semver
- 6.6.134 and later · up to and including 6.6.*not affected · semver
- 6.12.81 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.170-1	6.1.170-1
Debian:13	linux	before 6.12.85-1	6.12.85-1
Debian:14	linux	before 6.18.10-1	6.18.10-1
SUSE:Linux Enterprise Live Patching 15 SP7	kernel-livepatch-SLE15-SP7-RT_Update_11	before 1-150700.1.3.1	1-150700.1.3.1
SUSE:Linux Micro 6.1	kernel-default	before 6.4.0-41.1	6.4.0-41.1
SUSE:Linux Micro 6.1	kernel-default-base	before 6.4.0-41.1.21.18	6.4.0-41.1.21.18
SUSE:Linux Micro 6.1	kernel-kvmsmall	before 6.4.0-41.1	6.4.0-41.1
SUSE:Linux Micro 6.1	kernel-rt	before 6.4.0-41.1	6.4.0-41.1
SUSE:Linux Micro 6.1	kernel-source	before 6.4.0-41.1	6.4.0-41.1
SUSE:Linux Micro 6.1	kernel-source-rt	before 6.4.0-41.1	6.4.0-41.1
SUSE:Linux Micro Extras 6.2	kernel-obs-build	before 6.12.0-160000.33.1	6.12.0-160000.33.1
SUSE:Linux Micro Extras 6.2	kernel-syms	before 6.12.0-160000.33.1	6.12.0-160000.33.1
SUSE:Real Time Module 15 SP7	kernel-rt	before 6.4.0-150700.7.37.2	6.4.0-150700.7.37.2
SUSE:Real Time Module 15 SP7	kernel-source-rt	before 6.4.0-150700.7.37.2	6.4.0-150700.7.37.2
SUSE:Real Time Module 15 SP7	kernel-syms-rt	before 6.4.0-150700.7.37.1	6.4.0-150700.7.37.1

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-2026-23269Mar 18, 2026 · apparmor: validate DFA start states are in bounds in unpack_pdb
28Monitor
← EarlierCVE-2025-71268Mar 18, 2026 · btrfs: fix reservation leak in some error paths when inserting inline extent
22Monitor
Later →CVE-2026-23253Mar 18, 2026 · media: dvb-core: fix wrong reinitialization of ringbuffer on reopen
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 / package	Fixed version	Source
Linux Linux	0a1fbbd780f04d1b6cf48dd327c866ba937de1c4	Vendor (CNA)
Linux Linux	3a9fd45afadec1fbfec72057b9473d509fa8b68c	Vendor (CNA)
Linux Linux	3edd1f6c7c520536b62b2904807033597554dbac	Vendor (CNA)
Linux Linux	6de3a371a8b9fd095198b1aa68c22cc10a4c6961	Vendor (CNA)
Linux Linux	f8da41de0bff9eb1d774a7253da0c9f637c4470a	Vendor (CNA)
azl3 kernel 6.6.130.1-3 on Azure Linux 3.0	6.6.134.1-2 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.170-1 · Debian:12	Package registry (OSV)
suse:kernel-default	6.4.0-41.1 · SUSE:Linux Micro 6.1	Package registry (OSV)
suse:kernel-default-base	6.4.0-41.1.21.18 · SUSE:Linux Micro 6.1	Package registry (OSV)
suse:kernel-kvmsmall	6.4.0-41.1 · SUSE:Linux Micro 6.1	Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7-RT_Update_11	1-150700.1.3.1 · SUSE:Linux Enterprise Live Patching 15 SP7	Package registry (OSV)
suse:kernel-obs-build	6.12.0-160000.33.1 · SUSE:Linux Micro Extras 6.2	Package registry (OSV)
suse:kernel-rt	6.4.0-150700.7.37.2 · SUSE:Real Time Module 15 SP7	Package registry (OSV)
suse:kernel-source	6.4.0-41.1 · SUSE:Linux Micro 6.1	Package registry (OSV)
suse:kernel-source-rt	6.4.0-150700.7.37.2 · SUSE:Real Time Module 15 SP7	Package registry (OSV)
suse:kernel-syms	6.12.0-160000.33.1 · SUSE:Linux Micro Extras 6.2	Package registry (OSV)
suse:kernel-syms-rt	6.4.0-150700.7.37.1 · SUSE:Real Time Module 15 SP7	Package 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.

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 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-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

SSVC exploitation— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

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

References

git.kernel.org/stable/c/0a1fbbd780f04d1b6cf48dd327c866ba937de1c4

Show all references (4 more)

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

All records