CVE-2026-98984: dcache: don't put a mountpoint on a dentry that's being removed
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
- Fixed version: Linux Linux 25e3ce3e2ebdd8ed3fc19dc1f7e3bc487f9240f3, 30a1625022411a387cce9239408ece9955bc9c58, 390ddcea2a8aca411b931a8e2863a80ccca8d2b3; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 25e3ce3e2ebdd8ed3fc19dc1f7e3bc487f9240f3, 30a1625022411a387cce9239408ece9955bc9c58, 390ddcea2a8aca411b931a8e2863a80ccca8d2b3; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: dcache: don't put a mountpoint on a dentry that's being removed rmdir(), unlink() and rename() call dont_mount() on the victim and then detach_mounts() with the victim's inode locked. do_lock_mount() takes the inode lock of the mountpoint and checks cant_mount() so a mount can't show up after detach_mounts(). But attach_recursive_mnt() makes a second mountpoint for the root of the source mount so that the mounts already located at the destination can be put on top of it. No inode is locked for that one and d_set_mounted() only refuses a dentry that is unlinked. Between detach_mounts() and d_delete() the victim is still hashed: rmrace: b passed dont_mount() and detach_mounts(), sleeping T2: move_mount(S, /tmp/plcant/x, BENEATH) = 0 errno 0 () T1: rmdir(/tmp/plcant/d/b) = 0 errno 0 109 107 0:61 /d/b//deleted /tmp/plcant/x rw,relatime - tmpfs tmpfs rw 108 109 0:63 / /tmp/plcant/x rw,relatime - tmpfs T rw A bind mount of the directory that's being removed is moved beneath an existing mount while the rmdir() is located between the two calls. The mount ends up on the removed directory and nothing will ever detach it. Check cant_mount() in d_set_mounted() as well. dont_mount() raises the flag under d_lock before detach_mounts() runs so either the mountpoint is set first and detach_mounts() finds the mount or the flag is seen and the mount is refused.
- Published
- Oct 23, 2026
- Updated
- Oct 30, 2026
- EPSS
- 0.1% · 7th percentile
- CWE
- —
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 5e6ef5ef6eaf690faad3a7c6c665ebf45d7b6ccf, 839d42687dfce0ed0ea2c6bd8d707cc0e276fbe7, 808e83e5add13152bd4a88346487de68395c136b, 6de9d08a9718ee9c12ba6343c50141c2d633e3dc, 4.11affected
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 25e3ce3e2ebdd8ed3fc19dc1f7e3bc487f9240f3affected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 982d231ad863bb14f7bda4852ab942c0203cec4baffected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 96ca40461d8b91e13061ec4afb59bae6f07a516aaffected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 5e6bfd9f249f2c74bb63c0f06ad959da3bee0971affected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 793cb67b0f52d00c67bd0e76bc57455b5c70ebb8affected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 390ddcea2a8aca411b931a8e2863a80ccca8d2b3affected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 30a1625022411a387cce9239408ece9955bc9c58affected · git
- 1064f874abc0d05eeed8993815f584d847b72486 and later · before 75f4197f1e11d2eb75c2d6f916a7d4764db621e5affected · git
- 4.1.40 and later · before 4.2affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | from 0 | — |
| Debian:13 | linux | before 6.12.113-1 | 6.12.113-1 |
| Debian:14 | linux | before 7.2.11-1 | 7.2.11-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-98982Oct 23, 2026 · namespace: don't let a pseudo dentry become the root of a mount31Monitor
- ← EarlierCVE-2026-98983Oct 23, 2026 · unshare: don't drop active namespace references that were never taken0Monitor
- Later →CVE-2026-98985Oct 23, 2026 · namespace: check the mounts before reading their parents in pivot_root()0Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 25e3ce3e2ebdd8ed3fc19dc1f7e3bc487f9240f3 | Vendor (CNA) |
| Linux Linux | 30a1625022411a387cce9239408ece9955bc9c58 | Vendor (CNA) |
| Linux Linux | 390ddcea2a8aca411b931a8e2863a80ccca8d2b3 | Vendor (CNA) |
| Linux Linux | 4.10 | Vendor (CNA) |
| Linux Linux | 4.11 | Vendor (CNA) |
| Linux Linux | 4.2 | Vendor (CNA) |
| Linux Linux | 4.5 | Vendor (CNA) |
| Linux Linux | 5e6bfd9f249f2c74bb63c0f06ad959da3bee0971 | Vendor (CNA) |
| Linux Linux | 75f4197f1e11d2eb75c2d6f916a7d4764db621e5 | Vendor (CNA) |
| Linux Linux | 793cb67b0f52d00c67bd0e76bc57455b5c70ebb8 | Vendor (CNA) |
| Linux Linux | 96ca40461d8b91e13061ec4afb59bae6f07a516a | Vendor (CNA) |
| Linux Linux | 982d231ad863bb14f7bda4852ab942c0203cec4b | Vendor (CNA) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 | 6.6.161.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.113-1 · Debian:13 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 7, 2026+15 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1390 · Oct 26, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/30a1625022411a387cce9239408ece9955bc9c58
- git.kernel.org/stable/c/390ddcea2a8aca411b931a8e2863a80ccca8d2b3
- git.kernel.org/stable/c/5e6bfd9f249f2c74bb63c0f06ad959da3bee0971
- git.kernel.org/stable/c/75f4197f1e11d2eb75c2d6f916a7d4764db621e5
- git.kernel.org/stable/c/793cb67b0f52d00c67bd0e76bc57455b5c70ebb8
- git.kernel.org/stable/c/96ca40461d8b91e13061ec4afb59bae6f07a516a
- git.kernel.org/stable/c/982d231ad863bb14f7bda4852ab942c0203cec4b
Vendor advisories and official records. Exploit/PoC links are deliberately left out.