Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-98989— namespace: check a recursive bind mount for mount namespace loops

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Linux 内核中，以下漏洞已得到修复： 命名空间（namespace）：检查递归绑定挂载是否会导致挂载命名空间循环 函数拒绝将某个挂载命名空间自身的文件（或其祖先命名空间的文件）进行绑定挂载，前提是该命名空间的创建时间不早于调用者的命名空间。因为如果某个挂载命名空间持有自身文件或祖先文件的挂载，就会形成循环依赖。然而，该函数目前仅检查了绑定挂载起始位置的目录项（dentry）。 当使用 标志进行递归挂载时，源路径下的所有内容都会被复制，且 会传递 标志，导致源路径下所有的挂载命名空间文件也被一并复制。 对于调

AI Predicted 7.8 Difficulty: Moderate EPSS 0.17% · P6

Affected Version Matrix 8

VendorProduct Version RangeStatus
Linux Linux e149ed2b805fefdccf7ccdfc19eca22fdd4514ac< a0ba48256f5dff6f75a45f8ce39fe57f21df1022 affected
e149ed2b805fefdccf7ccdfc19eca22fdd4514ac< 37a82f400efa4d263542a5fa41755b21057f1e5d affected
e149ed2b805fefdccf7ccdfc19eca22fdd4514ac< c640a01a78e42302879006ed7b7d5a9a943ba815 affected
3.19 affected
< 3.19 unaffected
6.18.57≤ 6.18.* unaffected
7.2.11≤ 7.2.* unaffected
7.3≤ * unaffected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-98989

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
namespace: check a recursive bind mount for mount namespace loops
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: namespace: check a recursive bind mount for mount namespace loops do_loopback() refuses to bind mount the file of a mount namespace that is as old as the caller's or older because a mount namespace that holds a mount of its own file, or of an ancestor's, would cause a cycle. But it only checks the dentry the bind mount starts from. With MS_REC everything below it is copied and do_loopback() passes CL_COPY_MNT_NS_FILE so mount namespace files below the source are copied. That's fine for a source in the caller's own mount namespace. Every mount namespace file in there passed the same check when it was bind-mounted. It isn't fine for a source in another mount namespace. may_copy_tree() accepts a bind mount of any nsfs or pidfs file no matter what mount namespace it lives in so that /proc/<pid>/ns/<ns> and pidfds can be bind mounted. If we create a bind-mount stack of mount namespaces file descriptors the kernel will copy them irrespective of their ancestoral relationship to the mount namespace in question: 151 146 0:7 net:[4026531833] /tmp/nrc/y rw - nsfs nsfs rw 152 151 0:7 mnt:[4026532293] /tmp/nrc/y rw - nsfs nsfs rw Mount 152 is a mount of the mount namespace file of mount namespace 4026532293 inside mount namespace 4026532293. That namespace and every mount in it are leaked... All it takes is a process in an older mount namespace that stacks the file and repeating it leaks without limit: after control: Shmem: 380 kB child: mount(/proc/self/fd/6, MS_BIND|MS_REC): ok after cycle: Shmem: 65916 kB do_move_mount() runs check_for_nsfs_mounts() over a detached tree for exactly that reason. Do the same for the copy before it is grafted.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux e149ed2b805fefdccf7ccdfc19eca22fdd4514ac ~ a0ba48256f5dff6f75a45f8ce39fe57f21df1022 -
Linux Linux 3.19 -

II. Public POCs for CVE-2026-98989

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-98989

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-98989 (2)

Same Patch Batch · Linux · 2026-10-23 · 217 CVEs total

CVE-2026-98959 9.8 CRITICAL btrfs: fix xattr replace when multiple xattrs are packed in the same item
CVE-2026-99078 9.8 CRITICAL net/mlx5e: Prevent stale XSK buffer release on MPWQE refill retry
CVE-2026-99079 9.8 CRITICAL net/mlx5e: Prevent stale XSK buffer release on refill retry
CVE-2026-98988 8.8 HIGH namespace: keep covered mounts covered in OPEN_TREE_NAMESPACE
CVE-2026-99083 8.8 HIGH ksmbd: fix heap out-of-bounds write in krb5_authenticate()
CVE-2026-99082 8.8 HIGH KVM: x86: Use active memslots for the per-vCPU MMIO cache
CVE-2026-98870 8.8 HIGH ksmbd: remove stale channels from all sessions on teardown
CVE-2026-98980 8.8 HIGH namei: don't reveal overmounted entries in refwalk
CVE-2026-98981 8.8 HIGH namespace: unhash a dentry before detaching the mounts on it
CVE-2026-99042 8.4 HIGH io_uring/net: populate CONNECT filter fields for 24-byte sockaddr_in6
CVE-2026-98978 8.4 HIGH namespace: never expire a locked mount
CVE-2026-99064 8.1 HIGH cipso: adjust cached option offsets when removing CIPSO
CVE-2026-98968 8.1 HIGH amt: send the relay's General Query directly from the receive path
CVE-2026-98944 7.8 HIGH HID: steam: Refactor registration
CVE-2026-99053 7.8 HIGH tipc: hold a reference to nodes found by link name
CVE-2026-99054 7.8 HIGH tipc: destroy topsrv workqueues before closing connections
CVE-2026-99056 7.8 HIGH strparser: make sure __strp_recv isn't running before tearing down the parser
CVE-2026-99002 7.8 HIGH drm/vmwgfx: validate pitch coming from userspace
CVE-2026-98899 7.8 HIGH netfilter: ipset: mark the rcu locked areas properly
CVE-2026-99006 7.8 HIGH drm/i915/gem: Prevent overstepping exec array boundary

Showing top 20 of 217 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux