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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-98260: exec: Cleanup POSIX timers right after de_thread()

Noroxi assessment

Priority: Monitor (action score 31/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 6f1977cea3e85cd8ab55fb337d3e1725fe61d1ce, 75aa08b93c65766040f9ca99f41ac85ad22596b6, acb03d3881818581052924a9bbbe92b8741ed448; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.

Low priority for now. Upgrade to Linux Linux 6f1977cea3e85cd8ab55fb337d3e1725fe61d1ce, 75aa08b93c65766040f9ca99f41ac85ad22596b6, acb03d3881818581052924a9bbbe92b8741ed448; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: exec: Cleanup POSIX timers right after de_thread() A per-thread CPU timer holds a reference to the PID of the thread it is attached to and, while it is armed, its node is queued in that thread's posix_cputimers. The task is looked up by that PID. When a non-leader thread exec()s, de_thread() changes which task owns that PID. pid_task(timer->it.cpu.pid, PIDTYPE_PID) then returns NULL, but the node is still queued on tsk, which is alive. timer_lock_sighand() takes a failed lookup to mean that the node is already dequeued, so it has nothing to undo. begin_new_exec() calls posix_cpu_timers_exit(me) right after exec_task_namespaces() and that removes the leftover node, so the state normally stays invisible. But bprm->point_of_no_return is set before de_thread(), so if unshare_files(), set_mm_exe_file(), exec_mmap() or exec_task_namespaces() fails, the task dies before it gets there. exit_itimers() then frees the k_itimer while its node is still queued, and reaping tsk later erases that freed node from the rbtree. In short: the non-leader thread B the parent timer_create(CLOCK_THREAD_CPUTIME_ID) timer_settime() arm_timer() // the node is queued on B execve() de_thread(B) exchange_tids(B, leader) // B's PID now belongs to the leader release_task(leader) __exit_signal(leader) posix_cpu_timers_exit(leader) // cleans leader's queue, not B's __unhash_process(leader) // that PID has no task anymore exec_mmap() mmap_read_lock_killable(old_mm) kill(B, SIGKILL) // -EINTR get_signal() do_exit() exit_itimers() posix_timer_delete() posix_cpu_timer_del() posix_timer_unhash_and_free() // freed while still queued wait4() release_task(B) posix_cpu_timers_exit(B) cleanup_timerqueue() timerqueue_del() // use-after-free Move the POSIX timer cleanup right after de_thread() before any of the later failure conditions brings the task into do_exit(). [ tglx: Move the cleanup right after de_thread() ]

HighCVSS 7.8 · v3.1—Proof of concept Fix available
Published
Oct 6, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 8th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Proof of concept exists, no weaponized module
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.7affected
    • 55e8c8eb2c7b6bf30e99423ccfe7ca032f498f59 and later · before f6c93e8ecaaf12959b7ef6eb611351001db2ff5daffected · git
    • 55e8c8eb2c7b6bf30e99423ccfe7ca032f498f59 and later · before 6f1977cea3e85cd8ab55fb337d3e1725fe61d1ceaffected · git
    • 55e8c8eb2c7b6bf30e99423ccfe7ca032f498f59 and later · before d9ae467e617ca29b825493a362bf0d75ad5f4ac3affected · git
    • 55e8c8eb2c7b6bf30e99423ccfe7ca032f498f59 and later · before 75aa08b93c65766040f9ca99f41ac85ad22596b6affected · git
    • 55e8c8eb2c7b6bf30e99423ccfe7ca032f498f59 and later · before d602877baf36c43c788a5f472c977e0be414029faffected · git
    • 55e8c8eb2c7b6bf30e99423ccfe7ca032f498f59 and later · before acb03d3881818581052924a9bbbe92b8741ed448affected · git
    • before 5.7not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.158 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.67.1.el10_26.12.0-211.67.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-98258Oct 6, 2026 · posix-cpu-timers: Prevent freeing a timer which is queued on the expiry list
    31Monitor
  • ← EarlierCVE-2026-98259Oct 6, 2026 · fs/dax: check zero or empty entry before converting xarray entry
    0Monitor
  • Later →CVE-2026-98261Oct 6, 2026 · cifs: Fix server use-after-free in cifs_chan_skip_or_disable()
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux6f1977cea3e85cd8ab55fb337d3e1725fe61d1ceVendor (CNA)
Linux Linux75aa08b93c65766040f9ca99f41ac85ad22596b6Vendor (CNA)
Linux Linuxacb03d3881818581052924a9bbbe92b8741ed448Vendor (CNA)
Linux Linuxd602877baf36c43c788a5f472c977e0be414029fVendor (CNA)
Linux Linuxd9ae467e617ca29b825493a362bf0d75ad5f4ac3Vendor (CNA)
Linux Linuxf6c93e8ecaaf12959b7ef6eb611351001db2ff5dVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · Release NotesMicrosoft (MSRC)
almalinux:kernel6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.67.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux7.2.8-1 · Debian:14Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-55.111.1.el10_0 · Red Hat:enterprise_linux_eus:10.0Package registry (OSV)

+6

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×35

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12026-10-18
Proof-of-concept repository on GitHubstars:432026-10-18
Proof-of-concept repository on GitHubstars:332026-10-20
Proof-of-concept repository on GitHubstars:232026-10-23
Proof-of-concept repository on GitHubstars:52026-10-23
Proof-of-concept repository on GitHubstars:12026-10-24
Proof-of-concept repository on GitHubstars:312026-10-25
Proof-of-concept repository on GitHubstars:42026-10-25
Proof-of-concept repository on GitHubstars:02026-10-26
Proof-of-concept repository on GitHubstars:22026-10-26
Proof-of-concept repository on GitHubstars:182026-10-26
Proof-of-concept repository on GitHubstars:32026-10-26

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. First PoC+12 d
  4. TodayNov 4, 2026+29 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturitynone → poc
  2. CVSS— → 7.8
  3. Severity— → high
  4. Exploit maturity— → none
  5. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records