CVE-2026-31449
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Modified
Affected
- Linux Kernel < 6.12.80
- Linux Kernel < 6.18.21
- Linux Kernel < 6.19.11
- Linux Kernel 2.6.19
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31449.md and follow it. Check whether this project is affected by CVE-2026-31449. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/01bf1e0b997d82c0e353b51ed74ef99698043c33
- https://git.kernel.org/stable/c/2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8
- https://git.kernel.org/stable/c/407c944f217c17d4343148011acafebc604d55e1
- https://git.kernel.org/stable/c/93f2e975ed658ce09db4d4c2877ca2c06540df83
References
- https://git.kernel.org/stable/c/01bf1e0b997d82c0e353b51ed74ef99698043c33
- https://git.kernel.org/stable/c/10242e640b36b91ad03d25f3dc77854bbdff8358
- https://git.kernel.org/stable/c/2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8
- https://git.kernel.org/stable/c/39d6e2b67651614bac0dc6592fa9836321910067
- https://git.kernel.org/stable/c/407c944f217c17d4343148011acafebc604d55e1
- https://git.kernel.org/stable/c/4d08401aa13f1531216f1a7ae281ca4806e90a5c
- https://git.kernel.org/stable/c/93f2e975ed658ce09db4d4c2877ca2c06540df83
- https://git.kernel.org/stable/c/c5839b34704c9c2f47f079451bdbb22de0da1ed1
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html