High Memory corruption

CVE-2025-22121 — ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()

In the Linux kernel, the following vulnerability has been resolved: ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all() There's issue as follows: BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790 Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172 CPU: 3 PID: 15172 Comm: syz-executor.0 Call Trace: __dump_stack lib/dump_stack.c:82 [inline] dump_stack+0xbe/0xfd lib/dump_stack.c:123 print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560 kasan_report+0x3a/0x50 mm/kasan/report.c:585 ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137 ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896 ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323 evict+0x39f/0x880 fs/inode.c:622 iput_final fs/inode.c:1746 [inline] iput fs/inode.c:1772 [inline] iput+0x525/0x6c0 fs/inode.c:1758 ext4_orphan_cleanup fs/ext4/super.c:3298 [inline] ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300 mount_bdev+0x355/0x410 fs/super.c:1446 legacy_get_tree+0xfe/0x220 fs/fs_context.c:611 vfs_get_tree+0x8d/0x2f0 fs/super.c:1576 do_new_mount fs/namespace.c:2983 [inline] path_mount+0x119a/0x1ad0 fs/namespace.c:3316 do_mount+0xfc/0x110 fs/namespace.c:3329 __do_sys_mount fs/namespace.c:3540 [inline] __se_sys_mount+0x219/0x2e0 fs/namespace.c:3514 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Memory state around the buggy address: ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Above issue happens as ext4_xattr_delete_inode() isn't check xattr is valid if xattr is in inode. To solve above issue call xattr_check_inode() check if xattr if valid in inode. In fact, we can directly verify in ext4_iget_extra_inode(), so that there is no divergent verification.

Published Apr 16, 2025 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.21%

ahead of 10% of scored CVEs · Oct 14, 2026

Affects

Linux

Linux and 1 more

CVSS base

7.1

High · 3 source(s)

Prioritization reference: 8.4 provisional

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ e50e5129f384ae282adebfb561189cdb19b81cee and < 27202452b0bc942fdc3db72a44c4dcdab96d5b56≥ e50e5129f384ae282adebfb561189cdb19b81cee and < b374e9ecc92aaa7fb2ab221ee3ff5451118ab566≥ e50e5129f384ae282adebfb561189cdb19b81cee and < c000a8a9b5343a5ef867df173c6349672dacbd0f≥ e50e5129f384ae282adebfb561189cdb19b81cee and < 3c591353956ffcace2cc74d09930774afed60619≥ e50e5129f384ae282adebfb561189cdb19b81cee and < 098927a13fd918bd7c64c2de905350a1ad7b4a3a≥ e50e5129f384ae282adebfb561189cdb19b81cee and < 0c8fbb6ffb3c8f5164572ca88e4ccb6cd6a41ca8≥ e50e5129f384ae282adebfb561189cdb19b81cee and < 5701875f9609b000d91351eaa6bfd97fe2f157f4version 4.13	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 4.13 and < 6.14.2	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.4	CVSS 3.1	High	2.5	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.4	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP
7.1	CVSS 3.1	High	1.8	5.2	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.4 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-125 · Out-of-bounds Read

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 7.1
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Modified
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
2025
CVE published
Apr 16, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

9 on the record

git.kernel.org/stable/c/5701875f9609b000d91351eaa6bfd97fe2f157f4
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/0c8fbb6ffb3c8f5164572ca88e4ccb6cd6a41ca8
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/27202452b0bc942fdc3db72a44c4dcdab96d5b56
NIST National Vulnerability Database
cert-portal.siemens.com/productcert/html/ssa-457936.html
NIST National Vulnerability Database
git.kernel.org/stable/c/c000a8a9b5343a5ef867df173c6349672dacbd0f
NIST National Vulnerability Database
git.kernel.org/stable/c/b374e9ecc92aaa7fb2ab221ee3ff5451118ab566
NIST National Vulnerability Database
git.kernel.org/stable/c/098927a13fd918bd7c64c2de905350a1ad7b4a3a
NIST National Vulnerability Database
cert-portal.siemens.com/productcert/html/ssa-019113.html
NIST National Vulnerability Database
git.kernel.org/stable/c/3c591353956ffcace2cc74d09930774afed60619
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Memory corruption
same class

CWE-125
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CISA SSVC assessment.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-22121 is "ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.