CVE-2026-43493: Linux kernel · crypto: pcrypt – Fix handling of MAY_BACKLOG requests
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in eb34e243df57e32f4c08fa191f3602ea19076276 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in eb34e243df57e32f4c08fa191f3602ea19076276, ae7e95638d956d556d74b9abb9e780d3bd3dcd9e, 76641449b28979ebd6c02e9598367e119e385236 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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
|
| 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
|
Description
In the Linux kernel, the following vulnerability has been resolved: crypto: pcrypt - Fix handling of MAY_BACKLOG requests MAY_BACKLOG requests can return EBUSY. Handle them by checking for that value and filtering out EINPROGRESS notifications.
References
- git.kernel.org/stable/c/ae7e95638d956d556d74b9abb9e780d3bd3dcd9e (opens in a new tab)
- git.kernel.org/stable/c/1d7f07df450bac3301938fbc4251f2611be4084e (opens in a new tab)
- git.kernel.org/stable/c/76641449b28979ebd6c02e9598367e119e385236 (opens in a new tab)
- git.kernel.org/stable/c/9f1cbca178c03188e201ed175251372149bb25f2 (opens in a new tab)
- git.kernel.org/stable/c/eb34e243df57e32f4c08fa191f3602ea19076276 (opens in a new tab)
- git.kernel.org/stable/c/77d55bc8675ee851ed639dc9be77325a8024cf67 (opens in a new tab)
- git.kernel.org/stable/c/46271895ddfb1ba41f89f7e0dffbe9c2bcf7380a (opens in a new tab)
- git.kernel.org/stable/c/915b692e6cb723aac658c25eb82c58fd81235110 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)