CVE-2026-23047
In the Linux kernel, the following vulnerability has been resolved: libceph: make calc_target() set t->paused, not just clear it Currently calc_target() clears t->paused if the request shouldn't be paused anymore, but doesn't ever set t->paused even though it's able to determine when the request should be paused. Setting t->paused is left to __submit_request() which is fine for regular requests but doesn't work for linger requests -- since __submit_request() doesn't operate on linger requests, there is nowhere for lreq->t.paused to be set. One consequence of this is that watches don't get reestablished on paused -> unpaused transitions in cases where requests have been paused long enough for the (paused) unwatch request to time out and for the subsequent (re)watch request to enter the paused state. On top of the watch not getting reestablished, rbd_reregister_watch() gets stuck with rbd_dev->watch_mutex held: rbd_register_watch __rbd_register_watch ceph_osdc_watch linger_reg_commit_wait It's waiting for lreq->reg_commit_wait to be completed, but for that to happen the respective request needs to end up on need_resend_linger list and be kicked when requests are unpaused. There is no chance for that if the request in question is never marked paused in the first place. The fact that rbd_dev->watch_mutex remains taken out forever then prevents the image from getting unmapped -- "rbd unmap" would inevitably hang in D state on an attempt to grab the mutex.
Affected versions
Linux kernel versions
4.7
and later are affected. Fixed in
5.10.248,
5.15.198,
6.1.161,
6.6.121,
6.12.66,
6.18.6,
6.19
and their respective stable series.
References
The following references provide additional information about CVE-2026-23047 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/2b3329b3c29d9e188e40d902d5230c2d5989b940
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PatchKernel patch commithttps://git.kernel.org/stable/c/4d3399c52e0e61720ae898f5a0b5b75d4460ae24
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PatchKernel patch commithttps://git.kernel.org/stable/c/4ebc711b738d139cabe2fc9e7e7749847676a342
Frequently asked questions
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What is CVE-2026-23047?
CVE-2026-23047 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.7 onward and has been patched in 5.10.248, 5.15.198, 6.1.161 and others. CVE-2026-23047 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-23047?
Yes — CVE-2026-23047 has been patched. Fixed versions include 5.10.248, 5.15.198, 6.1.161 and others. If you are running Linux kernel 4.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-23047 actively exploited?
No — CVE-2026-23047 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.