CVE-2026-64600xfs: resample the data fork mapping after cycling ILOCK
- 7.8HighCVSS base score
- 0.47%Exploitation in 30 daysEPSS · top 59% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: xfs: resample the data fork mapping after cycling ILOCK xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode, a data fork mapping, and a cow fork mapping. Unfortunately, these two helpers cycle the ILOCK to grab a transaction, which means that the mappings are stale as soon as we reacquire the ILOCK. Currently we refresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but we don't refresh the data fork mapping beforehand, which means that the xfs_bmap_trim_cow in that function queries the refcount btree about the wrong physical blocks and returns an inaccurate value in *shared. If *shared is now false, the directio write proceeds with a stale data fork mapping. Fix this by querying the data fork mapping if the sequence counter changes across the ILOCK cycle.
Timeline
ID reserved
By Linux
- 4 days later
· 4 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.47% · top 59% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < dc11be133efca5fe3a2fb02b016dee825cc12f18
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < b8c9aa832b52680ee40d6cab0efb081f9a69df05
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < 50f0012da1040f69a4e788cd9aed587c9a04983f
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < e705d81a7193dd19e69b8e2bad4696d78a4ea075
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < 206c09b04dc5469c7ff14d8aceff2d47c88078d9
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < 44f891bc088958399eec27f7604928694aa35581
- affected 3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5 – < 2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7
- affected 4.11
- unaffected < 4.11
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.96 – ≤ 6.12.*
- unaffected 6.18.39 – ≤ 6.18.*
- unaffected 7.1.4 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References14
- https://git.kernel.org/stable/c/dc11be133efca5fe3a2fb02b016dee825cc12f18 (opens in a new tab)
- https://git.kernel.org/stable/c/b8c9aa832b52680ee40d6cab0efb081f9a69df05 (opens in a new tab)
- https://git.kernel.org/stable/c/50f0012da1040f69a4e788cd9aed587c9a04983f (opens in a new tab)
- https://git.kernel.org/stable/c/e705d81a7193dd19e69b8e2bad4696d78a4ea075 (opens in a new tab)
- https://git.kernel.org/stable/c/206c09b04dc5469c7ff14d8aceff2d47c88078d9 (opens in a new tab)
- https://git.kernel.org/stable/c/44f891bc088958399eec27f7604928694aa35581 (opens in a new tab)
- https://git.kernel.org/stable/c/2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7 (opens in a new tab)
- https://cdn2.qualys.com/advisory/2026/07/22/RefluXFS.txt (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/07/22/14 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/07/22/18 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/07/22/19 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/07/31/3 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/03/4 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/03/8 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-47879 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64600)Record last updated .