CVE-2026-115505

high

Description

libsmb2 before 6.3 contains integer overflow vulnerabilities in the DCE/RPC NDR decoder in lib/dcerpc.c that allow heap out-of-bounds reads and writes. A malicious SMB server or machine-in-the-middle on unsigned connections can send crafted NetrShareEnum replies with wrapping actual_count or max_count values when clients call smb2_share_enum_async(), corrupting heap memory.

References

https://www.vulncheck.com/advisories/libsmb2-before-6.3-integer-overflow-in-dce-rpc-ndr-decoder-via-netrshareenum

https://hackmd.io/@haindpwn/libsmb2-dcerpc-ndr-count-overflow-oob

https://github.com/sahlberg/libsmb2/releases/tag/libsmb2-6.3

https://github.com/sahlberg/libsmb2/issues/496

https://github.com/sahlberg/libsmb2/commit/a79f6914cb5ed3f74293d15cdea901261ce179ff

https://github.com/sahlberg/libsmb2

Details

Source: Mitre, NVD

Published: 2026-10-22

Updated: 2026-10-22

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:C

Severity: High

CVSS v3

Base Score: 7.6

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

Severity: High

CVSS v4

Base Score: 7.2

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

Severity: High