Answer in brief
CVE-2026-74484 records a Unknown severity vulnerability in binfmt_misc: don't let an 'F' entry pin its own instance. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=948b701a607f123df92ed29084413e5dd8cda2ed <1cc2decee06acc939337304e9b3f737fd5d8c4bd || >=948b701a607f123df92ed29084413e5dd8cda2ed <4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b || >=948b701a607f123df92ed29084413e5dd8cda2ed <098e92fe0f1bde5af99c8cf504f13f01ef139f85 || >=948b701a607f123df92ed29084413e5dd8cda2ed <79055d82772b9584f259b747fe40ff56a076678d | 1cc2decee06acc939337304e9b3f737fd5d8c4bd, 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b, 098e92fe0f1bde5af99c8cf504f13f01ef139f85, 79055d82772b9584f259b747fe40ff56a076678d |
| Linux/Linuxgeneric | 4.8 | Not reported |
| Linux/Linuxgeneric | >=21ca59b365c091d583f36ac753eaa8baf947be6f <1cc2decee06acc939337304e9b3f737fd5d8c4bd || >=21ca59b365c091d583f36ac753eaa8baf947be6f <4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b || >=21ca59b365c091d583f36ac753eaa8baf947be6f <098e92fe0f1bde5af99c8cf504f13f01ef139f85 || >=21ca59b365c091d583f36ac753eaa8baf947be6f <79055d82772b9584f259b747fe40ff56a076678d | 1cc2decee06acc939337304e9b3f737fd5d8c4bd, 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b, 098e92fe0f1bde5af99c8cf504f13f01ef139f85, 79055d82772b9584f259b747fe40ff56a076678d |
| Linux/Linuxgeneric | 6.7 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.