CVE-2026-80697: Linux kernel · erofs: ensure valid f_path for page cache sharing
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.7 Medium.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Aug 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.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
No explicit patch links or vendor advisories are provided in the input data. Users should monitor official Linux kernel releases and update to versions that include the fix for this issue once available.
Description
In the Linux kernel, the following vulnerability has been resolved: erofs: ensure valid f_path for page cache sharing Previously, backing files for page cache sharing were set up with f_path left as NULL (only f_inode was valid). It worked, but a recent mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on 7.2-rc4): BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy) Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 RIP: 0010:__do_sys_mincore+0xc0/0x2c0 ... Specify valid paths using valid disconnected dentries together with erofs_ishare_mnt instead of leaving f_path empty, so they are more like real backing files in a pseudo filesystem and standard backing_file_open() can be used directly.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80697 (opens in a new tab)
- git.kernel.org/stable/c/3879657c4ffd81b9a42cf575fc6cb60201032587 (opens in a new tab)
- git.kernel.org/stable/c/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80697 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80697 (opens in a new tab)
- git.kernel.org/linus/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443 (opens in a new tab)