What is CVE-2026-98080?

CVE-2026-98080 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 4.14.45 onward and patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98080 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-98080?

CVE-2026-98080 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-98080?

Yes, CVE-2026-98080 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 4.14.45 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-98080 actively exploited?

CVE-2026-98080 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-98080

Medium

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not force reloc root creation during qgroup_account_snapshot() [BUG] When running btrfs/252 with quota enabled through MKFS_OPTIONS="-O quota", it has a high chance to trigger the following kernel warning and flips the fs RO: BTRFS info (device dm-2): relocating block group 30408704 flags metadata|dup ------------[ cut here ]------------ WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x74b/0x960 [btrfs], CPU#4: btrfs/2173 CPU: 4 UID: 0 PID: 2173 Comm: btrfs Not tainted 7.2.0-rc6-custom+ #457 PREEMPT(full) 3adc6528fb66f7a55fe1095385818e742f200aab Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:lookup_inline_extent_backref+0x74b/0x960 [btrfs] Call Trace: <TASK> insert_inline_extent_backref+0x7c/0x160 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __btrfs_inc_extent_ref+0xa9/0x270 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __btrfs_run_delayed_refs+0x4af/0x11c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_run_delayed_refs+0x9d/0xf0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] create_pending_snapshot+0x39d/0xf00 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] create_pending_snapshots+0x9b/0xc0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_commit_transaction+0x280/0xeb0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] prepare_to_relocate+0x147/0x200 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] relocate_block_group+0x6b/0x5e0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_relocate_block_group+0x92c/0x2380 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_relocate_chunk+0x3f/0x1a0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_balance+0xa2c/0x19c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_ioctl+0x2839/0x2d30 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __x64_sys_ioctl+0x416/0x9a0 do_syscall_64+0xe1/0x790 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> ---[ end trace 0000000000000000 ]--- BTRFS info (device dm-2): leaf 4593991680 gen 233 total ptrs 175 free space 5953 owner 2 BTRFS info (device dm-2): refs 3 lock_owner 2173 current 2173 item 0 key (166772736 METADATA_ITEM 1) itemoff 16250 itemsize 33 extent refs 1 gen 222 flags 2 ref#0: tree block backref root 266 [ Skip the tree dump ] item 174 key (263225344 METADATA_ITEM 0) itemoff 10328 itemsize 33 extent refs 1 gen 162 flags 258 ref#0: tree block backref root 267 BTRFS error (device dm-2): extent item not found for insert, bytenr 179847168 num_bytes 16384 parent 4594335744 root_objectid 273 owner 0 offset 0 BTRFS error (device dm-2): failed to run delayed ref for logical 179847168 num_bytes 16384 type 182 action 1 ref_mod 1: -117 [CAUSE] The above error is showing that there is a tree reference to a metadata extent that is no longer there. With "ref_verify" mount option (requires CONFIG_BTRFS_DEBUG), there is some extra debug output: BTRFS error (device dm-2): dumping block entry [180961280 16384], num_refs 0, metadata 1, from disk 0 BTRFS error (device dm-2): root entry 256, num_refs 18446744073709551615 BTRFS error (device dm-2): root entry 273, num_refs 18446744073709551615 BTRFS error (device dm-2): Ref action 3, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 1 btrfs_force_cow_block+0x129/0x7d0 [btrfs] btrfs_cow_block+0x10a/0x250 [btrfs] btrfs_search_slot+0x5eb/0xf40 [btrfs] btrfs_insert_empty_items+0x3a/0x70 [btrfs] insert_with_overflow+0x53/0x130 [btrfs] btrfs_insert_dir_item+0x125/0x290 [btrfs] btrfs_add_link+0xaa/0x410 [btrfs] btrfs_rename+0x5ea/0xcd0 [btrfs] btrfs_rename2+0x28/0x60 [btrfs] vfs_rename+0x5b2/0xe10 filename_renameat2+0x244/0x430 __x64_sys_rename+0x48/0x70 do_syscall_64+0xe1/0x790 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ---truncated---

Package Linux Kernel

Published 2026-09-25

Last modified 2026-10-06

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-672

CVE-2026-98080 is classified as CWE-672

See CWE-672 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 4.14.45, 4.16.13, 4.17 and later are affected. Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2.7, 7.3-rc2 and their respective stable series.

Affected from

≥ 4.14.45 ≥ 4.16.13 ≥ 4.17

Fixed in

✓ 5.10.271 5.10.x ✓ 5.15.222 5.15.x ✓ 6.1.189 6.1.x ✓ 6.6.158 6.6.x ✓ 6.12.111 6.12.x ✓ 6.18.53 6.18.x ✓ 7.2.7 7.2.x ✓ 7.3-rc2

References

8 total

Kernel Git
https://git.kernel.org/stable/c/203cbfb4fba590bd9b08bd36fa6d05b5d28923bf

Patch
Kernel Git
https://git.kernel.org/stable/c/21bd77c132f18dc21c6fcdf417310d1adcf7448b

Patch
Kernel Git
https://git.kernel.org/stable/c/7caaae233a55e167063f4cfa3385b1a04c8bbecb

Patch
Kernel Git
https://git.kernel.org/stable/c/7ce02d52548b672795511c2cac8da6ec79ac8877

Patch
Kernel Git
https://git.kernel.org/stable/c/b5d5ab5a715001dd937c920ef8c5688fd4999ba1

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-98080

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-09-25

Modified 2026-10-06

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-98080?

CVE-2026-98080 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.14.45 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98080 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-98080?

CVE-2026-98080 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-98080?

Yes. CVE-2026-98080 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 4.14.45 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-98080 actively exploited?

No. CVE-2026-98080 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.