CVE-2026-74484: binfmt_misc: don't let an 'F' entry pin its own instance
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: 0.16% (FIRST EPSS).
- Fixed version: Linux Linux 098e92fe0f1bde5af99c8cf504f13f01ef139f85, 1cc2decee06acc939337304e9b3f737fd5d8c4bd, 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 098e92fe0f1bde5af99c8cf504f13f01ef139f85, 1cc2decee06acc939337304e9b3f737fd5d8c4bd, 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b 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: binfmt_misc: don't let an 'F' entry pin its own instance An entry registered with 'F' opens its interpreter at registration time and holds that file until the entry is freed. Any entry nobody removes by hand only gets closed once the binfmt_misc superblock is shut down. If the interpreter lives on a mount that keeps that superblock alive the two pin each other: binfmt_misc sb -> inode -> entry -> interp_file -> vfsmount -> binfmt_misc sb TL;DR the file is never closed. Once the mount namespace is gone there is nothing left to unregister through either. There are two ways to trigger this bug: - Point the interpreter at the instance itself. Its files are regular files owned by the mounter and both bm_get_inode() and simple_fill_super() leave i_op at empty_iops. So notify_change() falls back to simple_setattr() and chmod +x works. We never set SB_I_NOEXEC and so open_exec() accepts it. - Use the instance as an overlayfs lower layer. The overlay superblock holds a clone_private_mount() of every layer until it is destroyed and that clone is in no namespace. So umount_tree() never reaches it. That's a DoS. And it isn't only the superblock that leaks. It pins the user namespace it was mounted in, so every iteration permanently eats one of the caller's user namespace charges. So let's just do the sane thing. SB_I_NOEXEC makes open_exec() fail on the instance's own files and s_stack_depth makes overlayfs reject the layer before it ever takes a clone. That also covers the ecryptfs and fuse passthrough variants. What 'F' promises is unchanged. The stable tag is narrower than the Fixes tags on purpose. Before sandboxed mounts this needed global root against the single instance everyone shares, and the change doesn't apply to those trees anyway. Note that SB_I_NODEV is implicitly raised for userns mounts but raise it explicitly here as well.
- Published
- Aug 15, 2026
- Updated
- Aug 19, 2026
- EPSS
- 0.1% · 6th 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.
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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
- 6.7affected
- 21ca59b365c091d583f36ac753eaa8baf947be6f and later · before 1cc2decee06acc939337304e9b3f737fd5d8c4bdaffected · git
- 21ca59b365c091d583f36ac753eaa8baf947be6f and later · before 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2baffected · git
- 21ca59b365c091d583f36ac753eaa8baf947be6f and later · before 098e92fe0f1bde5af99c8cf504f13f01ef139f85affected · git
- 21ca59b365c091d583f36ac753eaa8baf947be6f and later · before 79055d82772b9584f259b747fe40ff56a076678daffected · git
- before 6.7not affected · semver
- 6.12.103 and later · up to and including 6.12.*not affected · semver
- 6.18.44 and later · up to and including 6.18.*not affected · semver
- 7.1.8 and later · up to and including 7.1.*not affected · semver
- 7.2 and laternot affected · original_commit_for_fix
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-6.12 | before 6.12.107-1~deb12u1 | 6.12.107-1~deb12u1 |
| Debian:13 | linux | before 6.12.105-1 | 6.12.105-1 |
| Debian:14 | linux | before 7.1.8-1 | 7.1.8-1 |
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-2026-74478Aug 15, 2026 · um: vector: fix use-after-free in vector_mmsg_rx()39Monitor
- ← EarlierCVE-2026-74483Aug 15, 2026 · binfmt_misc: don't leak the user namespace when the mount fails0Monitor
- Later →CVE-2026-74486Aug 15, 2026 · binfmt_misc: use exe_file_deny_write_access() for the interpreter clone0Monitor
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 | 098e92fe0f1bde5af99c8cf504f13f01ef139f85 | Vendor (CNA) |
| Linux Linux | 1cc2decee06acc939337304e9b3f737fd5d8c4bd | Vendor (CNA) |
| Linux Linux | 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b | Vendor (CNA) |
| Linux Linux | 79055d82772b9584f259b747fe40ff56a076678d | Vendor (CNA) |
| debian:linux | 6.12.105-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | 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.
No dated events beyond publication.
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.
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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-26-0854 · Aug 19, 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
- Fix✗ → ✓
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References
Show all references (3 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.