CVE-2026-45957: Linux kernel · rcu: Fix rcu_read_unlock() deadloop due to softirq
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in d41e37f26b3157b3f1d10223863519a943aa239b : patch Linux kernel soon.
Data as of 30 Oct 2026, 12:36 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- Patch
- Available – fixed in d41e37f26b3157b3f1d10223863519a943aa239b, d36d8a7cf0e1d52ccde290855782b7b2ffc78f63, c2932e16d8c354404b17123e64daa8e33191e145 +3
Exploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix for this vulnerability is available in the Linux kernel. The issue was resolved by commits that set a defer_qs_pending flag before calling raise_softirq_irqoff(). Users should update to a fixed kernel version containing these commits to mitigate the issue.
Description
CVE-2026-45957 is a vulnerability in the Linux kernel affecting version 5.8 where the rcu_read_unlock() function could enter an infinite deadloop due to issues with softirq handling and recursion protection removal. This was caused by a change that removed recursion-protection code, leading to a deadloop in raise_softirq_irqoff() when ftrace is enabled. The issue was fixed by setting a flag before calling raise_softirq_irqoff() to prevent the deadloop.
References
- git.kernel.org/stable/c/d36d8a7cf0e1d52ccde290855782b7b2ffc78f63 (opens in a new tab)
- git.kernel.org/stable/c/979c708e6c9d7fc461daef2dad8b45f22e23464c (opens in a new tab)
- git.kernel.org/stable/c/1f16679a5aa60238466ce339c35f5e82ece60337 (opens in a new tab)
- git.kernel.org/stable/c/4a4a6e12c9c829be3f74b7206fa8640fc4e1c566 (opens in a new tab)
- git.kernel.org/stable/c/c2932e16d8c354404b17123e64daa8e33191e145 (opens in a new tab)
- git.kernel.org/stable/c/d41e37f26b3157b3f1d10223863519a943aa239b (opens in a new tab)