Is there a public exploit for CVE-2026-99174?

No public exploit for CVE-2026-99174 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

— Unscored

In the Linux kernel, the following vulnerability has been resolved: ext4: free the sbi after a grace period ext4getlink() follows a symlink…

CVE-2026-99174

In the Linux kernel, the following vulnerability has been resolved: ext4: free the sbi after a grace period ext4getlink() follows a symlink that keeps its target in a data block in rcu pathwalk mode with ext4getblk(EXT4GETBLOCKSCACHEDNOWAIT). That reads smountstate in the ASSERT() of ext4getblk() and again in ext4eslookupextent(), and the lookup bumps the extent status hit or miss counter, all through sb->sfsinfo. ext4putsuper() destroys those counters, clears sb->sfsinfo and frees the sbi without waiting for a grace period. A pathwalk that is still in ext4getlink() when the last reference to the mount goes away then dereferences a NULL sfsinfo, the freed sbi or the destroyed percpu counters. With a pathwalk held up in ext4getlink() while the last reference goes away: KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af] RIP: 0010:ext4getblk+0xf0/0x640 Call Trace: ext4getlink+0x26c/0x410 picklink+0xf96/0x1780 stepintoslowpath+0x9b8/0x1250 pathlookupat+0x484/0xb00 filenamelookup+0x1f1/0x5b0 vfsstatx+0xd7/0x3b0 vfsfstatat+0x4d/0x90 dosysnewfstatat+0xa0/0x100 dosyscall64+0x10e/0x5e0 entrySYSCALL64afterhwframe+0x77/0x7f So far that has been hard to hit. umount(2)…

Assessment

CVSS: Not yet scored
Severity: Unscored
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 28 October 2026
Last updated: 30 October 2026
Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

At the source

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