CVE-2026-46159: btrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak
Noroxi assessment
Priority: Monitor (action score 18/100)
- 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: 0.09% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: Linux Linux 4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3, 5d12e0ab009ade48c1bff9324fd9bea2c773d088, 973e57c726c1f8e77259d1c8e519519f1e9aea77; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3, 5d12e0ab009ade48c1bff9324fd9bea2c773d088, 973e57c726c1f8e77259d1c8e519519f1e9aea77; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1 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: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak btrfs_ioctl_space_info() has a TOCTOU race between two passes over the block group RAID type lists. The first pass counts entries to determine the allocation size, then the second pass fills the buffer. The groups_sem rwlock is released between passes, allowing concurrent block group removal to reduce the entry count. When the second pass fills fewer entries than the first pass counted, copy_to_user() copies the full alloc_size bytes including trailing uninitialized kmalloc bytes to userspace. Fix by copying only total_spaces entries (the actually-filled count from the second pass) instead of alloc_size bytes, and switch to kzalloc so any future copy size mismatch cannot leak heap data.
- Published
- May 28, 2026
- Updated
- Oct 15, 2026
- EPSS
- 0.0% · 0th percentile
- CWE
- CWE-367
Report tools
Action score
18
Monitor
Low priority for now.
- CVSS
- 18 / 40 · 4.7 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.0%
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.
Running WordPress? Scan your site free with WP Lens
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.
We use this product, ask for helpAffected 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 kernel2.6.34.1 and later · before 6.6.140
- linux linux kernel6.7 and later · before 6.12.90
- linux linux kernel6.13 and later · before 6.18.32
- linux linux kernel6.19 and later · before 7.0.7
- linux linux kernel2.6.34
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
- 2.6.34affected
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before f407aad350bdea4db300c47433573b7a41630d33affected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before d8224b1be6627c6c3b204bfb264508d27c65ac44affected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before d69a4a6813fdba7c4cc3695a7e843842b240790daffected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before f5ee467b56764964027c361641f64953fc0f8f9aaffected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before 4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3affected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before 5d12e0ab009ade48c1bff9324fd9bea2c773d088affected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before d09d67d5de577cedae3de9497dff217e0ac8b641affected · git
- 7fde62bffb576d384ea49a3aed3403d5609ee5bc and later · before 973e57c726c1f8e77259d1c8e519519f1e9aea77affected · git
- before 2.6.34not 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 6.1.176-1 | 6.1.176-1 |
| Debian:13 | linux | before 6.12.90-1 | 6.12.90-1 |
| Debian:14 | linux | before 7.0.7-1 | 7.0.7-1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-64kb | before 5.14.21-150400.24.225.2 | 5.14.21-150400.24.225.2 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-docs | before 5.14.21-150400.24.225.1 | 5.14.21-150400.24.225.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-obs-build | before 5.14.21-150400.24.225.2 | 5.14.21-150400.24.225.2 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-syms | before 5.14.21-150400.24.225.1 | 5.14.21-150400.24.225.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_56 | before 1-150400.9.3.2 | 1-150400.9.3.2 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default | before 5.14.21-150400.24.225.2 | 5.14.21-150400.24.225.2 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default-base | before 5.14.21-150400.24.225.2.150400.24.114.2 | 5.14.21-150400.24.225.2.150400.24.114.2 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-rt | before 5.14.21-150400.15.173.1 | 5.14.21-150400.15.173.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source | before 5.14.21-150400.24.225.2 | 5.14.21-150400.24.225.2 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source-rt | before 5.14.21-150400.15.173.1 | 5.14.21-150400.15.173.1 |
| SUSE:Linux Enterprise Server 15 SP4-LTSS | kernel-zfcpdump | before 5.14.21-150400.24.225.2 | 5.14.21-150400.24.225.2 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- 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 KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-46155May 28, 2026 · smb/client: fix out-of-bounds read in smb2_compound_op()36Monitor
- ← EarlierCVE-2026-46157May 28, 2026 · ALSA: pcm: oss: Fix data race at accessing runtime.oss.trigger31Monitor
- Later →CVE-2026-46161May 28, 2026 · md/raid10: fix divide-by-zero in setup_geo() with zero far_copies22Monitor
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 | 4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3 | Vendor (CNA) |
| Linux Linux | 5d12e0ab009ade48c1bff9324fd9bea2c773d088 | Vendor (CNA) |
| Linux Linux | 973e57c726c1f8e77259d1c8e519519f1e9aea77 | Vendor (CNA) |
| Linux Linux | d09d67d5de577cedae3de9497dff217e0ac8b641 | Vendor (CNA) |
| Linux Linux | d69a4a6813fdba7c4cc3695a7e843842b240790d | Vendor (CNA) |
| Linux Linux | d8224b1be6627c6c3b204bfb264508d27c65ac44 | Vendor (CNA) |
| Linux Linux | f407aad350bdea4db300c47433573b7a41630d33 | Vendor (CNA) |
| Linux Linux | f5ee467b56764964027c361641f64953fc0f8f9a | Vendor (CNA) |
| azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 | 6.6.141.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:linux | 6.1.176-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-64kb | 5.14.21-150400.24.225.2 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-default | 5.14.21-150400.24.225.2 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-default-base | 5.14.21-150400.24.225.2.150400.24.114.2 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-docs | 5.14.21-150400.24.225.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP4_Update_56 | 1-150400.9.3.2 · SUSE:Linux Enterprise Live Patching 15 SP4 | Package registry (OSV) |
| suse:kernel-obs-build | 5.14.21-150400.24.225.2 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-rt | 5.14.21-150400.15.173.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-source | 5.14.21-150400.24.225.2 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-source-rt | 5.14.21-150400.15.173.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-syms | 5.14.21-150400.24.225.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-zfcpdump | 5.14.21-150400.24.225.2 · SUSE:Linux Enterprise Server 15 SP4-LTSS | 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 researchersFinders, 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-2025-38352310 days apartposix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()KEV61This week
- CVE-2026-6409152 days apartbatman-adv: tt: fix TOCTOU race for reported vlans39Monitor
- CVE-2026-6403452 days apartnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer37Monitor
- CVE-2026-6393752 days apartKVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer35Monitor
- CVE-2026-6386752 days apartmptcp: close TOCTOU race while computing rcv_wnd32Monitor
- CVE-2026-4343320 days apartrust_binder: avoid reading the written value in offsets array31Monitor
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0290 · Jun 2, 2026(Linux Kernel Güvenlik Bildirimi)
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.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race ConditionCVSS vector
CVSS:3.1/AV:L/AC:H/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.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (8 more)Show less
- git.kernel.org/stable/c/5d12e0ab009ade48c1bff9324fd9bea2c773d088
- git.kernel.org/stable/c/973e57c726c1f8e77259d1c8e519519f1e9aea77
- git.kernel.org/stable/c/d09d67d5de577cedae3de9497dff217e0ac8b641
- git.kernel.org/stable/c/d69a4a6813fdba7c4cc3695a7e843842b240790d
- git.kernel.org/stable/c/d8224b1be6627c6c3b204bfb264508d27c65ac44
- git.kernel.org/stable/c/f407aad350bdea4db300c47433573b7a41630d33
- git.kernel.org/stable/c/f5ee467b56764964027c361641f64953fc0f8f9a
- cert-portal.siemens.com/productcert/html/ssa-784472.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.