How severe is CVE-2026-46299?

CVE-2026-46299 has a CVSS score of 7/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-46299?

Affected package information for CVE-2026-46299 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-46299?

No patched version of the affected component has shipped for CVE-2026-46299 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect CVE-2026-46299 in my code and dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-46299 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-46299?

O3 pinpoints whether CVE-2026-46299 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-46299 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-46299 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-46299?

CVE-2026-46299 has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 2th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2026-46299 published, and has it been updated?

CVE-2026-46299 was published on June 8, 2026 and was last updated on June 19, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-46299

HIGH

In the Linux kernel, the following vulnerability has been resolved: hfsplus: fix held lock freed on hfsplus_fill_super() hfsplus_fill_super() calls hfs_find_init() to initialize a…

Published

Jun 8, 2026

Updated

Jun 19, 2026

Affected

0 pkgs

Patched

None yet

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk2th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

In the Linux kernel, the following vulnerability has been resolved:

hfsplus: fix held lock freed on hfsplus_fill_super()

hfsplus_fill_super() calls hfs_find_init() to initialize a search structure, which acquires tree->tree_lock. If the subsequent call to hfsplus_cat_build_key() fails, the function jumps to the out_put_root error label without releasing the lock. The later cleanup path then frees the tree data structure with the lock still held, triggering a held lock freed warning.

Fix this by adding the missing hfs_find_exit(&fd) call before jumping to the out_put_root error label. This ensures that tree->tree_lock is properly released on the error path.

The bug was originally detected on v6.13-rc1 using an experimental static analysis tool we are developing, and we have verified that the issue persists in the latest mainline kernel. The tool is specifically designed to detect memory management issues. It is currently under active development and not yet publicly available.

We confirmed the bug by runtime testing under QEMU with x86_64 defconfig, lockdep enabled, and CONFIG_HFSPLUS_FS=y. To trigger the error path, we used GDB to dynamically shrink the max_unistr_len parameter to 1 before hfsplus_asc2uni() is called. This forces hfsplus_asc2uni() to naturally return -ENAMETOOLONG, which propagates to hfsplus_cat_build_key() and exercises the faulty error path. The following warning was observed during mount:

=========================
WARNING: held lock freed!
7.0.0-rc3-00016-gb4f0dd314b39 #4 Not tainted
-------------------------
mount/174 is freeing memory ffff888103f92000-ffff888103f92fff, with a lock still held there!
ffff888103f920b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x1e0
2 locks held by mount/174:
#0: ffff888103f960e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.constprop.0+0x167/0xa40
#1: ffff888103f920b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x1e0

stack backtrace:
CPU: 2 UID: 0 PID: 174 Comm: mount Not tainted 7.0.0-rc3-00016-gb4f0dd314b39 #4 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x82/0xd0
debug_check_no_locks_freed+0x13a/0x180
kfree+0x16b/0x510
? hfsplus_fill_super+0xcb4/0x18a0
hfsplus_fill_super+0xcb4/0x18a0
? __pfx_hfsplus_fill_super+0x10/0x10
? srso_return_thunk+0x5/0x5f
? bdev_open+0x65f/0xc30
? srso_return_thunk+0x5/0x5f
? pointer+0x4ce/0xbf0
? trace_contention_end+0x11c/0x150
? __pfx_pointer+0x10/0x10
? srso_return_thunk+0x5/0x5f
? bdev_open+0x79b/0xc30
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? vsnprintf+0x6da/0x1270
? srso_return_thunk+0x5/0x5f
? __mutex_unlock_slowpath+0x157/0x740
? __pfx_vsnprintf+0x10/0x10
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? mark_held_locks+0x49/0x80
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? irqentry_exit+0x17b/0x5e0
? trace_irq_disable.constprop.0+0x116/0x150
? __pfx_hfsplus_fill_super+0x10/0x10
? __pfx_hfsplus_fill_super+0x10/0x10
get_tree_bdev_flags+0x302/0x580
? __pfx_get_tree_bdev_flags+0x10/0x10
? vfs_parse_fs_qstr+0x129/0x1a0
? __pfx_vfs_parse_fs_qstr+0x3/0x10
vfs_get_tree+0x89/0x320
fc_mount+0x10/0x1d0
path_mount+0x5c5/0x21c0
? __pfx_path_mount+0x10/0x10
? trace_irq_enable.constprop.0+0x116/0x150
? trace_irq_enable.constprop.0+0x116/0x150
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? kmem_cache_free+0x307/0x540
? user_path_at+0x51/0x60
? __x64_sys_mount+0x212/0x280
? srso_return_thunk+0x5/0x5f
__x64_sys_mount+0x212/0x280
? __pfx___x64_sys_mount+0x10/0x10
? srso_return_thunk+0x5/0x5f
? trace_irq_enable.constprop.0+0x116/0x150
? srso_return_thunk+0x5/0x5f
do_syscall_64+0x111/0x680
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffacad55eae
Code: 48 8b 0d 85 1f 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 8
RSP: 002b

---truncated---

Detection & mitigation playbook

Vulnerability

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-46299 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-46299 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-46299. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: hfsplus: fix held lock freed on hfsplus_fill_super() hfsplus_fill_super() calls hfs_find_init() to initialize a search structure, which acquires tree->tree_lock. If the subsequent call to hfsplus_cat_build_key() fails, the function jumps to the out_put_root error label without releasing the lock. The later cleanup path then frees the tree data structure with the lock still held, triggering a held lock freed warning. Fix this by adding the missing hfs_find_exit(&fd) call before jumping to the out_put_root error label. This e

O3 Security · Impact-Aware SCA

Is CVE-2026-46299 in your dependencies?

O3 detects CVE-2026-46299 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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CVE-2026-46299

EPSS Exploitation Probability

Description

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2026-46299 in your dependencies?