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VulnerabilityPublished Updated

CVE-2026-93125: Linux kernel · bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in b6ac0b5732047d43172b9dfbe6b57b9b8de303c2 : patch Linux kernel soon.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in b6ac0b5732047d43172b9dfbe6b57b9b8de303c2, 2147065d3a4e1d5d42ae553fef165f17ec5e0e79, 93a20b14f8627b2d3486e3ec1d3f2e7275a506ec +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 17 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae, < b6ac0b5732047d43172b9dfbe6b57b9b8de303c2
Fixed in
  • b6ac0b5732047d43172b9dfbe6b57b9b8de303c2
LinuxLinuxAffected
  • ≥ eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae, < 2147065d3a4e1d5d42ae553fef165f17ec5e0e79
Fixed in
  • 2147065d3a4e1d5d42ae553fef165f17ec5e0e79
LinuxLinuxAffected
  • ≥ eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae, < 93a20b14f8627b2d3486e3ec1d3f2e7275a506ec
Fixed in
  • 93a20b14f8627b2d3486e3ec1d3f2e7275a506ec
LinuxLinuxAffected
  • ≥ eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae, < 56a3846830ac95a472297d0cbba75cbff29540bb
Fixed in
  • 56a3846830ac95a472297d0cbba75cbff29540bb
LinuxLinuxAffected
  • ≥ eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae, < 2aaf67f0516fde29620d0edfc29c01b9ea7ad430
Fixed in
  • 2aaf67f0516fde29620d0edfc29c01b9ea7ad430
LinuxLinuxAffected
  • =6.1
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max check_kfunc_args() detects a kfunc argument named rdonly_buf_size or rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64, and does not bound it. check_kfunc_call() later copies that value into the returned register's mem_size field: meta->r0_size = reg->var_off.value; ... regs[BPF_REG_0].mem_size = meta.r0_size; regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set gets truncated instead of causing a load-time rejection, so the verifier records a PTR_TO_MEM register with an approximately 4 GiB mem_size for whatever allocation the kfunc returned. A later access check against that register uses the truncated, wrong bound. Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the point meta->r0_size is set.

References

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