CVE-2026-53260
published 2026-06-25CVE-2026-53260: In the Linux kernel, the following vulnerability has been resolved: tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req(). syzbot reported a…
PriorityP352critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.29%
21.9th percentile
In the Linux kernel, the following vulnerability has been resolved:
tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().
The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.
Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.
This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.
Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the reqsk due to its listener's close().
Let's wrap mod_timer() and refcount_set() with
preempt_disable_nested() and preempt_enable_nested().
Note that inet_ehash_insert() holds the normal spin_lock()
(mutex in PREEMPT_RT), so it must be called outside of
preempt_disable_nested(), but this is fine.
The lookup path just ignores 0 sk_refcnt entries in ehash
and tries to create another reqsk, but this will fail at
inet_ehash_insert().
[0]:
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28, CPU#0: ktimers/0/16
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28
Code: e4 7d d1 0a 67 48 0f b9 3a eb 4a e8 38 3d 23 fd 48 8d 3d e1 7d d1 0a 67 48 0f b9 3a eb 37 e8 25 3d 23 fd 48 8d 3d de 7d d1 0a 48 0f b9 3a eb 24 e8 12 3d 23 fd 48 8d 3d db 7d d1 0a 67 48 0f
RSP: 0000:ffffc90000157948 EFLAGS: 00010246
RAX: ffffffff84a1301b RBX: 0000000000000003 RCX: ffff88801ca98000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8f72ae00
RBP: ffffffff99ae3b01 R08: ffff88801ca9800
Affected
34 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= d2d6422f8bd17c6bb205133e290625a564194496 < 889fc99967007e2493833515a645cb2d800f6742 | 889fc99967007e2493833515a645cb2d800f6742 |
| linux | linux | >= d2d6422f8bd17c6bb205133e290625a564194496 < de5a46f3b2c8d3cd20afa158bd3a725e3e3d6fd3 | de5a46f3b2c8d3cd20afa158bd3a725e3e3d6fd3 |
| linux | linux | >= d2d6422f8bd17c6bb205133e290625a564194496 < b183215ff714efb747d9d5a429322ba6404b5401 | b183215ff714efb747d9d5a429322ba6404b5401 |
| linux | linux | >= d2d6422f8bd17c6bb205133e290625a564194496 < e10902df24488ca722303133acfc82490f7d59ad | e10902df24488ca722303133acfc82490f7d59ad |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 6.12 < 7.0.13 | 7.0.13 |
| ubuntu | linux | — | — |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-aws-7.0 | — | — |
| ubuntu | linux-azure | — | — |
| ubuntu | linux-azure-7.0 | — | — |
| ubuntu | linux-azure-fde | — | — |
| ubuntu | linux-gcp | — | — |
| ubuntu | linux-gcp-7.0 | — | — |
| ubuntu | linux-gke | — | — |
| ubuntu | linux-hwe-7.0 | — | — |
| ubuntu | linux-ibm | — | — |
| ubuntu | linux-nvidia | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat9.8CRITICAL
vendor_ubuntu9.8CRITICAL
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Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2026-10-09·CVSS 5.5
CVE-2026-68372 [MEDIUM] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- NVIDIA Tegra memory controller driver;
- Network drivers;
- USB core drivers;
- GFS2 file system;
- OCFS2 file system;
- SMB network file system;
- SoundWire (SDCA) ASoC drivers;
- B.A.T.M.A.N. meshing protocol;
- Ceph Core library;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- Open vSwitch;
- RxRPC session sockets;
- SCTP protocol;
- TIPC protocol;
(CVE-2026-43095, CVE-2026-52914, CVE-2026-52931, CVE-2026-52955,
CVE-2026-52958, CVE-2026-52982, CVE-2026-52986, CVE
Ubuntu
Linux kernel (Oracle) vulnerabilities
vendor_ubuntu·2026-09-29·CVSS 9.1
CVE-2026-64191 [CRITICAL] Linux kernel (Oracle) vulnerabilities
Title: Linux kernel (Oracle) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were d
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2026-09-22·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were di
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-09-10·CVSS 9.8
CVE-2026-53215 [CRITICAL] Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- Hardware crypto device drivers;
- NVIDIA Tegra memory controller driver;
- Network drivers;
- GFS2 file system;
- OCFS2 file system;
- SMB network file system;
- B.A.T.M.A.N. meshing protocol;
- Ceph Core library;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- Open vSwitch;
- RxRPC session sockets;
- SCTP protocol;
- TIPC protocol;
(CVE-2026-52914, CVE-2026-52931, CVE-2026-52955, CVE-2026-52958,
CVE-2026-52982, CVE-2026-52986, CVE-2026-52993, CVE-2026-52999,
CVE-2026-53002, CVE-2026-53006, CVE-2
Ubuntu
Linux kernel (GCP) vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (GCP) vulnerabilities
Title: Linux kernel (GCP) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were disc
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-08-20·CVSS 7.8
CVE-2026-64531 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 architecture;
- InfiniBand drivers;
- Network drivers;
- Network traffic control;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- Open vSwitch;
- RxRPC session sockets;
- SCTP protocol;
(CVE-2026-46331, CVE-2026-52924, CVE-2026-53131, CVE-2026-53151,
CVE-2026-53175, CVE-2026-53176, CVE-2026-53186, CVE-2026-53212,
CVE-2026-53215, CVE-2026-53216, CVE-2026-53221, CVE-2026-53224,
CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53247,
CVE-2026-53260, CVE-2026-53359, CVE-2026-64531)
Instructions:
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-08-20·CVSS 7.0
CVE-2026-64234 [HIGH] Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 platform drivers;
- Cryptographic API;
- PSP security protocol;
- ARM32 architecture;
- ARM64 architecture;
- MIPS architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UML);
- x
Ubuntu
Linux kernel (NVIDIA BaseOS) vulnerabilities
vendor_ubuntu·2026-08-20·CVSS 7.0
CVE-2026-64109 [HIGH] Linux kernel (NVIDIA BaseOS) vulnerabilities
Title: Linux kernel (NVIDIA BaseOS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 platform drivers;
- Cryptographic API;
- PSP security protocol;
- ARM32 architecture;
- ARM64 architecture;
- MIPS architecture;
- PowerPC architecture;
- RISC-V architecture;
- S390 architecture;
- User-Mode Linux (UM
Ubuntu
Linux kernel (HWE) vulnerabilities
vendor_ubuntu·2026-08-18·CVSS 7.8
CVE-2026-53131 [HIGH] Linux kernel (HWE) vulnerabilities
Title: Linux kernel (HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 architecture;
- InfiniBand drivers;
- Network drivers;
- Network traffic control;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- RxRPC session sockets;
- SCTP protocol;
(CVE-2026-46331, CVE-2026-52924, CVE-2026-53131, CVE-2026-53151,
CVE-2026-53175, CVE-2026-53176, CVE-2026-53186, CVE-2026-53212,
CVE-2026-53215, CVE-2026-53216, CVE-2026-53221, CVE-2026-53224,
CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53247,
CVE-2026-53260, CVE-2026-53359)
Instructions: After a standard system up
Ubuntu
Linux kernel (AWS) vulnerabilities
vendor_ubuntu·2026-08-17·CVSS 7.8
CVE-2026-53225 [HIGH] Linux kernel (AWS) vulnerabilities
Title: Linux kernel (AWS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 architecture;
- InfiniBand drivers;
- Network drivers;
- Network traffic control;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- RxRPC session sockets;
- SCTP protocol;
(CVE-2026-46331, CVE-2026-52924, CVE-2026-53131, CVE-2026-53151,
CVE-2026-53175, CVE-2026-53176, CVE-2026-53186, CVE-2026-53212,
CVE-2026-53215, CVE-2026-53216, CVE-2026-53221, CVE-2026-53224,
CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53247,
CVE-2026-53260, CVE-2026-53359)
Instructions: After a standard system up
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2026-08-13·CVSS 7.8
CVE-2026-53216 [HIGH] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 architecture;
- InfiniBand drivers;
- Network drivers;
- Thunderbolt and USB4 drivers;
- Network traffic control;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- RxRPC session sockets;
- SCTP protocol;
(CVE-2026-46331, CVE-2026-52924, CVE-2026-53131, CVE-2026-53146,
CVE-2026-53147, CVE-2026-53148, CVE-2026-53149, CVE-2026-53150,
CVE-2026-53151, CVE-2026-53175, CVE-2026-53176, CVE-2026-53186,
CVE-2026-53212, CVE-2026-53215, CVE-2026-53216, CVE-2026-53221,
CVE-2026-53224, CVE-2026-53225, CVE-2026-
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-08-12·CVSS 7.8
CVE-2026-53215 [HIGH] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- x86 architecture;
- InfiniBand drivers;
- Network drivers;
- Network traffic control;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- RxRPC session sockets;
- SCTP protocol;
(CVE-2026-46331, CVE-2026-52924, CVE-2026-53131, CVE-2026-53151,
CVE-2026-53175, CVE-2026-53176, CVE-2026-53186, CVE-2026-53212,
CVE-2026-53215, CVE-2026-53216, CVE-2026-53221, CVE-2026-53224,
CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53247,
CVE-2026-53260, CVE-2026-53359)
Instructions: After a standard system update y
Red Hat
kernel: tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req()
vendor_redhat·2026-06-25·CVSS 9.8
CVE-2026-53260 [CRITICAL] kernel: tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req()
kernel: tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req()
In the Linux kernel, the following vulnerability has been resolved:
tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().
The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.
Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.
This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.
Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the req
GHSA
In the Linux kernel, the following vulnerability has been resolved: tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
ghsa_unreviewed·2026-06-25
CVE-2026-53260 In the Linux kernel, the following vulnerability has been resolved: tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
In the Linux kernel, the following vulnerability has been resolved:
tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
syzbot reported a weird reqsk->rsk_refcnt underflow in
__inet_csk_reqsk_queue_drop().
The captured reqsk_put() in __inet_csk_reqsk_queue_drop()
is called only when it successfully removes reqsk from ehash.
Moreover, reqsk_timer_handler() calls another reqsk_put()
after that.
This indicates that the reqsk was missing both refcnts for
ehash and the timer itself.
Since all the syzbot reports had PREEMPT_RT enabled, the only
possible scenario is that reqsk_queue_hash_req() is preempted
after mod_timer() and before refcount_set(), and then the timer
triggered after 1s aborts the reqsk due to its listener's close().
Let's wrap mod_timer() and refcount_s
No detection rules found.
No public exploits indexed.
2026-06-25
Published