CVE-2026-31537
CVE-2026-31537 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- EPSS exploit prediction: 0% (2nd percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-25430
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: smb: server: make use of smbdirect_socket.send_io.bcredits It turns out that our code will corrupt the stream of reassabled data transfer messages when we trigger an immendiate (empty) send. In order to fix this we'll have a single 'batch' credit per connection. And code getting that credit is free to use as much messages until remaining_length reaches 0, then the batch credit it given back and the next logical send can happen.
Frequently asked questions
- What is CVE-2026-31537?
- In the Linux kernel, the following vulnerability has been resolved: smb: server: make use of smbdirect_socket.send_io.bcredits It turns out that our code will corrupt the stream of reassabled data transfer messages when we trigger an immendiate (empty) send. In order to fix this we'll have a single 'batch' credit per connection. And code getting that credit is free to use as much messages until remaining_length reaches 0, then the batch credit it given back and the next logical send can happen.
- How severe is CVE-2026-31537?
- CVE-2026-31537 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-31537 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-31537?
- CVE-2026-31537 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-31537?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-31537 have an EU (EUVD) identifier?
- Yes. CVE-2026-31537 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25430.
- When was CVE-2026-31537 published?
- CVE-2026-31537 was published on 2026-04-24 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/34abd408c8ba24d7c97bd02ba874d8c714f49db1
- https://git.kernel.org/stable/c/5ef18a2e66f2f33fdac64437bddfb9fe6389fdc7
- https://git.kernel.org/stable/c/79242e7b6bc63efec28b7c235bc320806afce6c0
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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