CVE-2026-74723: btrfs: lzo: reject inline extents without valid headers
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.7%
EPSS score, percentile 51.9 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 9.8 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 2.6.38
Unaffected before 2.6.38; 6.6.160; 6.12.114; 6.18.57; 7.1.9; 7.2
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from a6fa6fae40ec to before 5d00c9c1c951 |
| Affected | from a6fa6fae40ec to before fd150d7c8e0a |
| Affected | from a6fa6fae40ec to before 056876c9db1e |
| Affected | from a6fa6fae40ec to before fc50b475ad27 |
| Affected | from a6fa6fae40ec to before 0fa78ef637de |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | 2.6.38 |
| Unaffected | before 2.6.38 |
| Unaffected | 6.6.160 |
| Unaffected | 6.12.114 |
| Unaffected | 6.18.57 |
| Unaffected | 7.1.9 |
| Unaffected | 7.2 |
Versions not listed are: affected.
Versions the record lists as unaffected: 6.6.160, 6.12.114, 6.18.57, 7.1.9, 7.2.
Source: CVE List, as of . About the data.
About this vulnerability
In the Linux kernel, the following vulnerability has been resolved: btrfs: lzo: reject inline extents without valid headers [BUG] For a crafted btrfs image, the following KASAN can be triggered when reading an inline lzo compressed file extent: BUG: KASAN: slab-out-of-bounds in lzo_decompress+0x57d/0x700 Read of size 4 at addr ffff888006f2e644 by task btrfs_lzo_inlin/77 Call Trace: <…
Summary: CVE record, as of .
- CISA has not added CVE-2026-74723 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 22 Aug 2026.
- The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.7% (percentile 51.9), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
btrfs: lzo: reject inline extents without valid headers
In the Linux kernel, the following vulnerability has been resolved: btrfs: lzo: reject inline extents without valid headers [BUG] For a crafted btrfs image, the following KASAN can be triggered when reading an inline lzo compressed file extent: BUG: KASAN: slab-out-of-bounds in lzo_decompress+0x57d/0x700 Read of size 4 at addr ffff888006f2e644 by task btrfs_lzo_inlin/77 Call Trace: <TASK> dump_stack_lvl+0x5b/0x70 print_report+0xd1/0x610 kasan_report+0xe0/0x110 __asan_report_load_n_noabort+0x13/0x20 lzo_decompress+0x57d/0x700 btrfs_decompress+0x140/0x1c0 uncompress_inline+0x147/0x1b0 btrfs_get_extent+0xb23/0x10a0 btrfs_do_readpage.constprop.0+0x538/0x1ac0 btrfs_readahead+0x32f/0x5f0 read_pages+0x16f/0x850 page_cache_ra_unbounded+0x296/0x490 do_page_cache_ra+0xd9/0x130 page_cache_sync_ra+0x3ee/0x6f0 filemap_get_pages+0x306/0x15c0 filemap_read+0x329/0xd00 btrfs_file_read_iter+0x1f8/0x2b0 vfs_read+0x4ef/0x720 ksys_read+0xf8/0x1d0 __x64_sys_read+0x71/0xb0 x64_sys_call+0x1ab0/0x1b70 do_syscall_64+0x61/0x470 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> [CAUSE] For an inline lzo compressed file extent, there should always be one lzo header, recording the total length of the compressed data, followed by one segment header, recording the compressed lzo payload. But if a crafted inline lzo compressed file extent contains only an lzo header, without the segment header or payload, lzo_decompress() will still try to read the segment header, causing a read beyond the item boundary. Furthermore if the inline lzo compressed file extent is the first item of the leaf, it will be at the extent buffer boundary. The above out-of-boundary read will go beyond the extent buffer boundary, triggering the above KASAN report. [FIX] Validate the total length of the inlined lzo compressed file extent, to make sure there is at least one LZO header and one segment header, and a non-zero payload. [ Rework the commit message to remove slop ]
Source: CVE List, as of . About the data.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
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