Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-31449: ext4: validate p_idx bounds in ext4_ext_correct_indexes

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.14% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 01bf1e0b997d82c0e353b51ed74ef99698043c33, 10242e640b36b91ad03d25f3dc77854bbdff8358, 2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8.

Low priority for now. Upgrade to Linux Linux 01bf1e0b997d82c0e353b51ed74ef99698043c33, 10242e640b36b91ad03d25f3dc77854bbdff8358, 2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8 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: validate p_idx bounds in ext4_ext_correct_indexes ext4_ext_correct_indexes() walks up the extent tree correcting index entries when the first extent in a leaf is modified. Before accessing path[k].p_idx->ei_block, there is no validation that p_idx falls within the valid range of index entries for that level. If the on-disk extent header contains a corrupted or crafted eh_entries value, p_idx can point past the end of the allocated buffer, causing a slab-out-of-bounds read. Fix this by validating path[k].p_idx against EXT_LAST_INDEX() at both access sites: before the while loop and inside it. Return -EFSCORRUPTED if the index pointer is out of range, consistent with how other bounds violations are handled in the ext4 extent tree code.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Apr 22, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 3th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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.

Follow CVE-2026-31449

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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 help

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 kernel2.6.19.1 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 kernel2.6.19
  • 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

    • 2.6.19affected
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 39d6e2b67651614bac0dc6592fa9836321910067affected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before c5839b34704c9c2f47f079451bdbb22de0da1ed1affected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 10242e640b36b91ad03d25f3dc77854bbdff8358affected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 4d08401aa13f1531216f1a7ae281ca4806e90a5caffected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 407c944f217c17d4343148011acafebc604d55e1affected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 93f2e975ed658ce09db4d4c2877ca2c06540df83affected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 01bf1e0b997d82c0e353b51ed74ef99698043c33affected · git
    • a86c61812637c7dd0c57e29880cffd477b62f2e7 and later · before 2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8affected · git
    • before 2.6.19not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.11-16.19.11-1

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-2026-31447Apr 22, 2026 · ext4: reject mount if bigalloc with s_first_data_block != 0
    31Monitor
  • ← EarlierCVE-2026-31448Apr 22, 2026 · ext4: avoid infinite loops caused by residual data
    37Monitor
  • Later →CVE-2026-31450Apr 22, 2026 · ext4: publish jinode after initialization
    35Monitor

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 Linux01bf1e0b997d82c0e353b51ed74ef99698043c33Vendor (CNA)
Linux Linux10242e640b36b91ad03d25f3dc77854bbdff8358Vendor (CNA)
Linux Linux2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8Vendor (CNA)
Linux Linux39d6e2b67651614bac0dc6592fa9836321910067Vendor (CNA)
Linux Linux407c944f217c17d4343148011acafebc604d55e1Vendor (CNA)
Linux Linux4d08401aa13f1531216f1a7ae281ca4806e90a5cVendor (CNA)
Linux Linux93f2e975ed658ce09db4d4c2877ca2c06540df83Vendor (CNA)
Linux Linuxc5839b34704c9c2f47f079451bdbb22de0da1ed1Vendor (CNA)
debian:linux6.1.176-1 · 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.

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.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (10 more)

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

All records