8.1

CVE-2026-93787: linux

CVSS: 8.1v3.1HighReceived
AliasesUBUNTU-CVE-2026-93787DEBIAN-CVE-2026-93787
Published 24-09-2026Last modified 03-10-2026
Open JSON

Vulnerability summary

CVE-2026-93787 is a high (CVSS 8.1) vulnerability in linux. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26.6% of scored vulnerabilities.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.34%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 4 · Related 4
SUSE-SU-2026:4665-1SUSE-SU-2026:4666-1SUSE-SU-2026:4667-1SUSE-SU-2026:4668-1

Timeline

  1. 24-09-2026
    PublishedVulnerability first disclosed.
  2. 03-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: bound dirent name against end of SMB response in cifs_filldir cifs_filldir() copies the entry name out of an SMB1 TRANS2_FIND_FIRST / FIND_NEXT response using a length (de.namelen) supplied by the server. The kmalloc'd SMB response buffer is bounded, but nothing checks that de.name + de.namelen still lies inside that buffer before the eventual filldir64() -> verify_dirent_name() -> memchr() reads namelen bytes. A hostile SMB1 server that returns an oversized FileNameLength in a directory entry therefore causes memchr() to read past the end of the response slab buffer. Reachable from any user who can list a directory on a CIFS mount served by an attacker-controlled server (getdents64() on the mounted directory): BUG: KASAN: slab-out-of-bounds in memchr+0x71/0x80 Read of size 1 at addr ffff88800e0640cc by task poc/115 Call Trace: dump_stack_lvl+0x64/0x80 print_report+0xce/0x620 kasan_report+0xec/0x120 memchr+0x71/0x80 filldir64+0x4c/0x6a0 cifs_filldir.constprop.0+0x9bb/0x1e00 cifs_readdir+0x2101/0x3380 iterate_dir+0x19c/0x520 __x64_sys_getdents64+0x126/0x210 do_syscall_64+0x107/0x5a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Pass the end-of-response pointer down to cifs_filldir() and reject entries whose name would extend past that boundary. This bug was discovered by Artiphishell's vTriage pipeline, which generated a userspace reproducer (an emulated hostile SMB1 server plus a getdents64() client) that reliably triggers the KASAN report on an unpatched kernel. The fix below was drafted with the Claude coding assistant; a userspace reproducer is available on request.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

25-09-202621-10-2026
EPSS score
0.34%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu169 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linuxAll versions (No fix recorded) | < 6.1.190-1 | < 6.12.111-1 | < 7.2.6-1
  • linux-6.12< 6.12.111-1~deb12u1
Linux1 product
  • linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 4cb3d79beee0fecc739ce07af915d503f29ae557 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < cf87ef1e62ed31a439064cef69d6eec38c68bd92 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6e3b965267b7313903baba2739992b1e2e92d540 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 03003506c86f90312b0966283662c42fcab66e4b | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < f8cf09a53a0dc1da298e9dd0ba5f21710cf119d6 | 2.6.12

3 vendors · 172 products

References

8 links