ext4: fix out-of-bounds read in ext4_read_inline_dir()
Noroxi assessment
Priority: Monitor (action score 36/100)
- 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: 0.69% (FIRST EPSS); higher than 52% of all records.
- Anyone who can reach it over the internet 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 1a1dea633b724a1c042dbcdb1fed27f410916688, 36bf17bb90cdf7a623499b624b05acde4d2feef5, 5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
Low priority for now. Upgrade to Linux Linux 1a1dea633b724a1c042dbcdb1fed27f410916688, 36bf17bb90cdf7a623499b624b05acde4d2feef5, 5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: ext4: fix out-of-bounds read in ext4_read_inline_dir() ext4_read_inline_dir() can read a dirent header past the end of its inline buffer, triggering a slab-out-of-bounds read during getdents64(): BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry Read of size 2 at addr ffff88800f3dd23c by task exploit/148 ... __ext4_check_dir_entry ext4_read_inline_dir iterate_dir The dirent payload lives in a buffer of exactly inline_size bytes: dir_buf = kmalloc(inline_size, GFP_NOFS); but iteration runs in a position space extra_offset bytes larger (extra_size = extra_offset + inline_size) so the synthetic "." and ".." land at their block-dir offsets. A dirent is formed at "dir_buf + pos - extra_offset", yet the ext4_check_dir_entry() length argument uses the larger extra_size. A position whose dirent header would extend past extra_size is therefore accepted, and the rescan loop's rec_len probe and ext4_check_dir_entry() dereference de->rec_len before the entry is rejected. Reject a position whose minimum-size dirent header would not fit within extra_size before forming de, in both the rescan and main loops, and pass inline_size rather than extra_size to ext4_check_dir_entry() so the length check matches the physical buffer.
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- EPSS
- 0.6% · 52th percentile
- CWE
- —
Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 36 / 40 · 9.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.6%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 9.1
- 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.
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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.
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.
—
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
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before d1e7c186555ad65554fd2f2b02f5a539aa35ae48affected · git
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before 5fd20d4e50dd6e460b3ea8e4396f8553d4526f8faffected · git
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before 1a1dea633b724a1c042dbcdb1fed27f410916688affected · git
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before b060861f662d4826dc700a1c3584243bb3474cfeaffected · git
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before 6702c7da86d8cdb88d0fc57166286e115ffeb8c0affected · git
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before 36bf17bb90cdf7a623499b624b05acde4d2feef5affected · git
- c4d8b0235aa98f8c26bf94d308be3fdd24154572 and later · before 9333cc809f0a89e001b814155a6cb8903a6274dfaffected · git
- before 3.10not affected · semver
- 5.15.221 and later · up to and including 5.15.*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 | all versions | — |
| Debian:12 | linux-6.12 | before 6.12.111-1~deb12u1 | 6.12.111-1~deb12u1 |
| Debian:13 | linux | before 6.12.111-1 | 6.12.111-1 |
| Debian:14 | linux | before 7.2.6-1 | 7.2.6-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-72421ipv4: fib: Don't ignore error route in local/main tables.40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
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 | 1a1dea633b724a1c042dbcdb1fed27f410916688 | Vendor (CNA) |
| Linux Linux | 36bf17bb90cdf7a623499b624b05acde4d2feef5 | Vendor (CNA) |
| Linux Linux | 5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f | Vendor (CNA) |
| Linux Linux | 6702c7da86d8cdb88d0fc57166286e115ffeb8c0 | Vendor (CNA) |
| Linux Linux | 9333cc809f0a89e001b814155a6cb8903a6274df | Vendor (CNA) |
| Linux Linux | b060861f662d4826dc700a1c3584243bb3474cfe | Vendor (CNA) |
| Linux Linux | d1e7c186555ad65554fd2f2b02f5a539aa35ae48 | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | — | Microsoft (MSRC) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | 6.6.157.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.111-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.111-1~deb12u1 · Debian:12 | 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.
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 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.
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
- Anyone who can reach it over the internet 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
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:N/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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (6 more)Show less
- git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5
- git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f
- git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0
- git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df
- git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe
- git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48
Vendor advisories and official records. Exploit/PoC links are deliberately left out.