CVE-2025-38696: debian debian_linux NULL Pointer Dereference
Vulnerability summary
CVE-2025-38696 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in debian debian_linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 7.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 29 · Related 25Timeline
- 04-09-2025PublishedVulnerability first disclosed.
- 23-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: MIPS: Don't crash in stack_top() for tasks without ABI or vDSO Not all tasks have an ABI associated or vDSO mapped, for example kthreads never do. If such a task ever ends up calling stack_top(), it will derefence the NULL ABI pointer and crash. This can for example happen when using kunit: mips_stack_top+0x28/0xc0 arch_pick_mmap_layout+0x190/0x220 kunit_vm_mmap_init+0xf8/0x138 __kunit_add_resource+0x40/0xa8 kunit_vm_mmap+0x88/0xd8 usercopy_test_init+0xb8/0x240 kunit_try_run_case+0x5c/0x1a8 kunit_generic_run_threadfn_adapter+0x28/0x50 kthread+0x118/0x240 ret_from_kernel_thread+0x14/0x1c Only dereference the ABI point if it is set. The GIC page is also included as it is specific to the vDSO. Also move the randomization adjustment into the same conditional.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
+0.01 pp
From 0.18% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu149 products
- linuxAll versions (No fix recorded) | < 5.15.0-163.173 | < 6.8.0-100.100
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1097.104 | < 6.8.0-1046.49
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.1.153-1 | < 6.12.43-1 | < 6.16.3-1
- debian_linuxEOL11.0
Linux2 products
- linux≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < ab18e48a503230d675e824a0d68a108bdff42503 | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < e78033e59444d257d095b73ce5d20625294f6ec2 | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < bd90dbd196831f5c2620736dc221db2634cf1e8e | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < 5b6839b572b503609b9b58bc6c04a816eefa0794 | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < f22de2027b206ddfb8a075800bb5d0dacf2da4b8 | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < 82d140f6aab5e89a9d3972697a0dbe1498752d9b | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < 24d098b6f69b0aa806ffcb3e18259bee31650b28 | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < cddf47d20b0325dc8a4e57b833fe96e8f36c42a4 | ≥ ea7e0480a4b695d0aa6b3fa99bd658a003122113, < e9f4a6b3421e936c3ee9d74710243897d74dbaa2 | 86717a97f9218de798c6d33e0014ab9325e18f56 | e4882348eaa9f5f052cb21d2a5aa99a063e4308b | ≥ 4.14.77, < 4.15 | ≥ 4.18.15, < 4.19 | 4.19
- linux_kernelEOL≥ 4.14.77, < 4.15 | ≥ 4.18.15, < 4.19 | ≥ 4.19.1, < 5.4.297 | ≥ 5.5, < 5.10.241 | ≥ 5.11, < 5.15.190 | ≥ 5.16, < 6.1.149 | ≥ 6.2, < 6.6.103 | ≥ 6.7, < 6.12.43 | ≥ 6.13, < 6.15.11 | ≥ 6.16, < 6.16.2 | 4.19 | 4.19:rc8
3 vendors · 153 products
