VulnerabilityPublished 28 May 2026Updated 9 Oct 2026

CVE-2026-46160: Linux kernel · btrfs: fix missing last_unlink_trans update when removing a directory

Affects Linux kernelSource GCVE Database

Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +74

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 28 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-28.28	Fixed in 7.0.0-28.28
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1009.9	Fixed in 7.0.0-1009.9
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected <7.0.0-1010.10	Fixed in 7.0.0-1010.10
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected <7.0.0-1009.9	Fixed in 7.0.0-1009.9
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1008.8	Fixed in 7.0.0-1008.8
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1003.4	Fixed in 7.0.0-1003.4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix missing last_unlink_trans update when removing a directory When removing a directory we are not updating its last_unlink_trans field, which can result in incorrect fsync behaviour in case some one fsyncs the directory after it was removed because it's holding a file descriptor on it. Example scenario: mkdir /mnt/dir1 mkdir /mnt/dir1/dir2 mkdir /mnt/dir3 sync -f /mnt # Do some change to the directory and fsync it. chmod 700 /mnt/dir1 xfs_io -c fsync /mnt/dir1 # Move dir2 out of dir1 so that dir1 becomes empty. mv /mnt/dir1/dir2 /mnt/dir3/ open fd on /mnt/dir1 call rmdir(2) on path "/mnt/dir1" fsync fd <trigger power failure> When attempting to mount the filesystem, the log replay will fail with an -EIO error and dmesg/syslog has the following: [445771.626482] BTRFS info (device dm-0): first mount of filesystem 0368bbea-6c5e-44b5-b409-09abe496e650 [445771.626486] BTRFS info (device dm-0): using crc32c checksum algorithm [445771.627912] BTRFS info (device dm-0): start tree-log replay [445771.628335] page: refcount:2 mapcount:0 mapping:0000000061443ddc index:0x1d00 pfn:0x7072a5 [445771.629453] memcg:ffff89f400351b00 [445771.629892] aops:btree_aops [btrfs] ino:1 [445771.630737] flags: 0x17fffc00000402a(uptodate|lru|private|writeback|node=0|zone=2|lastcpupid=0x1ffff) [445771.632359] raw: 017fffc00000402a fffff47284d950c8 fffff472907b7c08 ffff89f458e412b8 [445771.633713] raw: 0000000000001d00 ffff89f6c51d1a90 00000002ffffffff ffff89f400351b00 [445771.635029] page dumped because: eb page dump [445771.635825] BTRFS critical (device dm-0): corrupt leaf: root=5 block=30408704 slot=10 ino=258, invalid nlink: has 2 expect no more than 1 for dir [445771.638088] BTRFS info (device dm-0): leaf 30408704 gen 10 total ptrs 17 free space 14878 owner 5 [445771.638091] BTRFS info (device dm-0): refs 4 lock_owner 0 current 3581087 [445771.638094] item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160 [445771.638097] inode generation 3 transid 9 size 16 nbytes 16384 [445771.638098] block group 0 mode 40755 links 1 uid 0 gid 0 [445771.638100] rdev 0 sequence 2 flags 0x0 [445771.638102] atime 1775744884.0 [445771.660056] ctime 1775744885.645502983 [445771.660058] mtime 1775744885.645502983 [445771.660060] otime 1775744884.0 [445771.660062] item 1 key (256 INODE_REF 256) itemoff 16111 itemsize 12 [445771.660064] index 0 name_len 2 [445771.660066] item 2 key (256 DIR_ITEM 1843588421) itemoff 16077 itemsize 34 [445771.660068] location key (259 1 0) type 2 [445771.660070] transid 9 data_len 0 name_len 4 [445771.660075] item 3 key (256 DIR_ITEM 2363071922) itemoff 16043 itemsize 34 [445771.660076] location key (257 1 0) type 2 [445771.660077] transid 9 data_len 0 name_len 4 [445771.660078] item 4 key (256 DIR_INDEX 2) itemoff 16009 itemsize 34 [445771.660079] location key (257 1 0) type 2 [445771.660080] transid 9 data_len 0 name_len 4 [445771.660081] item 5 key (256 DIR_INDEX 3) itemoff 15975 itemsize 34 [445771.660082] location key (259 1 0) type 2 [445771.660083] transid 9 data_len 0 name_len 4 [445771.660084] item 6 key (257 INODE_ITEM 0) itemoff 15815 itemsize 160 [445771.660086] inode generation 9 transid 9 size 8 nbytes 0 [445771.660087] block group 0 mode 40777 links 1 uid 0 gid 0 [445771.660088] rdev 0 sequence 2 flags 0x0 [445771.660089] atime 1775744885.641174097 [445771.660090] ctime 1775744885.645502983 [445771.660091] mtime 1775744885.645502983 [445771.660105] otime 1775744885.641174097 [445771.660106] item 7 key (257 INODE_REF 256) itemoff 15801 itemsize 14 [445771.660107] index 2 name_len 4 [445771.660108] item 8 key (257 DIR_ITEM 2676584006) itemoff 15767 itemsize 34 [445771.660109] location key (2 ---truncated---

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-46160
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:25.10, Ubuntu:26.04:LTS
CVSS version: 3.1

References

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