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UBUNTU-CVE-2026-31554 High

UBUNTU-CVE-2026-31554

In the Linux kernel, the following vulnerability has been resolved: futex: Require sys_futex_requeue() to have identical flags Nicholas reported that his LLM found it was possible to create a UaF when sys_futex_requeue() is used with different flags. The initial motivation for allowing different flags was the variable sized futex, but since that hasn't been merged (yet), simply mandate the flags are identical, as is the case for the old style sys_futex() requeue operations.

Exploit probability Not scored
Published April 24, 2026
Required by Not available
Last source change August 18, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:24.04:LTS linux-gkeop

34 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-5.19

8 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.2

10 explicit affected versions

Ubuntu:24.04:LTS linux-lowlatency-hwe-6.11

7 explicit affected versions

Ubuntu:22.04:LTS linux-starfive-6.2

3 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.8

4 explicit affected versions

Ubuntu:25.10 linux

20 explicit affected versions

Ubuntu:22.04:LTS linux-starfive-6.5

11 explicit affected versions

Ubuntu:26.04:LTS linux-azure-fde

6 explicit affected versions

Ubuntu:18.04:LTS linux-oem

50 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.0

6 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.11

12 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.5

19 explicit affected versions

Ubuntu:24.04:LTS linux-hwe-6.14

10 explicit affected versions

Ubuntu:20.04:LTS linux-raspi2

6 explicit affected versions

Ubuntu:24.04:LTS linux-riscv

24 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-6.5

10 explicit affected versions

Ubuntu:22.04:LTS linux-ibm-6.8

37 explicit affected versions

Ubuntu:24.04:LTS linux-oem-6.8

26 explicit affected versions

Ubuntu:22.04:LTS linux-azure-5.19

7 explicit affected versions

Ubuntu:22.04:LTS linux-oracle-6.8

40 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.5

13 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia

44 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.14

35 explicit affected versions

Ubuntu:20.04:LTS linux-gke-5.15

18 explicit affected versions

Ubuntu:24.04:LTS linux-oracle

45 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.13

13 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.8

4 explicit affected versions

Ubuntu:16.04:LTS linux-hwe-edge

23 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-aws-fips

19 explicit affected versions

Ubuntu:24.04:LTS linux

52 explicit affected versions

Ubuntu:24.04:LTS linux-raspi-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.8

21 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-6.8

7 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.13

16 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2

10 explicit affected versions

Ubuntu:24.04:LTS linux-aws

48 explicit affected versions

Ubuntu:24.04:LTS linux-hwe-6.11

8 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.0

7 explicit affected versions

Ubuntu:20.04:LTS linux-riscv

12 explicit affected versions

Ubuntu:24.04:LTS linux-oracle-6.14

11 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.11

12 explicit affected versions

Ubuntu:24.04:LTS linux-azure-6.11

7 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.11

12 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.5

14 explicit affected versions

Ubuntu:25.10 linux-azure-fde

10 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-azure-fips

10 explicit affected versions

Ubuntu:22.04:LTS linux-intel-iot-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-intel-5.13

7 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-tegra

17 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.13

12 explicit affected versions

Ubuntu:24.04:LTS linux-oracle-6.17

10 explicit affected versions

Ubuntu:Pro:Realtime:22.04:LTS linux-realtime-6.8

41 explicit affected versions

Ubuntu:24.04:LTS linux-oem-6.14

16 explicit affected versions

Ubuntu:25.10 linux-gcp

17 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.8

27 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-edge

10 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.4

37 explicit affected versions

Ubuntu:24.04:LTS linux-azure-nvidia

10 explicit affected versions

Ubuntu:24.04:LTS linux-gcp-6.17

11 explicit affected versions

Ubuntu:22.04:LTS linux-oracle-6.5

13 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8

39 explicit affected versions

Ubuntu:24.04:LTS linux-azure-nvidia-6.14

3 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-6.2

10 explicit affected versions

Ubuntu:24.04:LTS linux-gcp-6.14

11 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.10

26 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.13

13 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.6

29 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.3

13 explicit affected versions

Ubuntu:24.04:LTS linux-riscv-6.14

12 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-lowlatency

41 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.8

40 explicit affected versions

Ubuntu:24.04:LTS linux-riscv-6.17

8 explicit affected versions

Ubuntu:18.04:LTS linux-gke-4.15

33 explicit affected versions

Ubuntu:22.04:LTS linux-riscv

23 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.8

10 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.3

10 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-fips

20 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-gcp-fips

19 explicit affected versions

Ubuntu:Nvidia-BlueField:24.04:LTS linux-bluefield

11 explicit affected versions

Ubuntu:24.04:LTS linux-azure-fde-6.14

5 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.11

12 explicit affected versions

Ubuntu:Pro:Realtime:24.04:LTS linux-realtime-6.17

11 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.8

7 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.2

12 explicit affected versions

Ubuntu:24.04:LTS linux-hwe-6.17

10 explicit affected versions

Ubuntu:25.10 linux-azure

16 explicit affected versions

Ubuntu:24.04:LTS linux-azure-6.14

5 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19

10 explicit affected versions

Ubuntu:22.04:LTS linux-oem-5.17

26 explicit affected versions

Ubuntu:24.04:LTS linux-azure

39 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.8

35 explicit affected versions

Ubuntu:24.04:LTS linux-raspi

48 explicit affected versions

Ubuntu:24.04:LTS linux-aws-6.14

11 explicit affected versions

Ubuntu:24.04:LTS linux-aws-6.17

10 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.2

13 explicit affected versions

Ubuntu:24.04:LTS linux-ibm

46 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.0

16 explicit affected versions

Ubuntu:24.04:LTS linux-gcp

50 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-5.19

3 explicit affected versions

Ubuntu:24.04:LTS linux-gcp-6.11

7 explicit affected versions

Ubuntu:25.10 linux-riscv

15 explicit affected versions

Ubuntu:20.04:LTS linux-gke

51 explicit affected versions

Ubuntu:25.10 linux-oracle

16 explicit affected versions

Ubuntu:24.04:LTS linux-oem-6.11

18 explicit affected versions

Ubuntu:Pro:Realtime:24.04:LTS linux-raspi-realtime

43 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.13

12 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-6.17

7 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.1

27 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.8

43 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-5.19

8 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.8

5 explicit affected versions

Ubuntu:Pro:Realtime:24.04:LTS linux-realtime

46 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5

13 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.11

13 explicit affected versions

Ubuntu:22.04:LTS linux-starfive-5.19

7 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-6.11

8 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.13

12 explicit affected versions

Ubuntu:Pro:Realtime:24.04:LTS linux-realtime-6.14

9 explicit affected versions

Ubuntu:18.04:LTS linux-azure

44 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.3

16 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.11

13 explicit affected versions

Ubuntu:20.04:LTS linux-azure-fde

26 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop-5.15

45 explicit affected versions

Ubuntu:18.04:LTS linux-gkeop-5.4

37 explicit affected versions

Ubuntu:24.04:LTS linux-lowlatency

50 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.5

14 explicit affected versions

Ubuntu:18.04:LTS linux-gcp

38 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.3

9 explicit affected versions

Ubuntu:25.10 linux-aws

17 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-5.19

11 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-6.8

39 explicit affected versions

Ubuntu:24.04:LTS linux-xilinx

18 explicit affected versions

Ubuntu:25.10 linux-raspi

14 explicit affected versions

Ubuntu:24.04:LTS linux-azure-fde

6 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.2

7 explicit affected versions

Ubuntu:24.04:LTS linux-azure-6.17

10 explicit affected versions

Ubuntu:24.04:LTS linux-realtime

1 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.5

13 explicit affected versions

Ubuntu:18.04:LTS linux-hwe

43 explicit affected versions

Ubuntu:24.04:LTS linux-oem-6.17

16 explicit affected versions

Ubuntu:22.04:LTS linux-aws-5.19

10 explicit affected versions

Ubuntu:22.04:LTS linux-allwinner-5.19

8 explicit affected versions

Ubuntu:24.04:LTS linux-gke

45 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.2

14 explicit affected versions

Ubuntu:18.04:LTS linux-azure-edge

4 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop

78 explicit affected versions

Ubuntu:25.10 linux-realtime

14 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.5

11 explicit affected versions

Ubuntu:22.04:LTS linux-realtime

1 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.8

39 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

related USN-8595-2
related USN-8608-1
related USN-8609-1

04 / EVIDENCE

Source records

Open Source Vulnerabilities UBUNTU-CVE-2026-31554

In the Linux kernel, the following vulnerability has been resolved: futex: Require sys_futex_requeue() to have identical flags Nicholas reported that his LLM found it was possible to create a UaF when sys_futex_requeue() is used with different flags. The initial motivation for allowing different flags was the variable sized futex, but since that hasn't been merged (yet), simply mandate the flags are identical, as is the case for the old style sys_futex() requeue operations.

View original source

05 / REFERENCES

Further evidence