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.
References6
- github.com/sahlberg/libsmb2
- github.com/sahlberg/libsmb2/commit/a79f6914cb5ed3f74293d15cdea9…
- github.com/sahlberg/libsmb2/issues/496
- github.com/sahlberg/libsmb2/releases/tag/libsmb2-6.3
- hackmd.io/@haindpwn/libsmb2-dcerpc-ndr-count-overflow-oob
- www.vulncheck.com/advisories/libsmb2-before-6.3-integer-overflo…
Metrics
- CVSS 3.1
-
7.6
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H - CVSS 4.0
-
7.2
HIGH
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 11 · as of 8 November 2026
- CWE
- CWE-190
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