CVE-2026-115505

libsmb2 before 6.3 Integer Overflow in DCE/RPC NDR Decoder via NetrShareEnum

HIGH 7.2EPSS 0.2%

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.

Affected: sahlberg · libsmb2
CVSS v4.0 VULNCHECK: 7.2 HIGHCVSS: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
CVSS v3.1 VULNCHECK: 7.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
EPSS: 0.21% chance of exploitation in the next 30 days, 11th percentile
Published: 2026-10-22
Updated: 2026-10-29

Proof-of-concept exploits (1)

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

CVE references

sahlberg/libsmb2REFERENCE
sahlberg/libsmb2/commit/a79f6914cb5ed3f74293d15cdea901261ce179ffPATCH
sahlberg/libsmb2/issues/496REFERENCE
sahlberg/libsmb2/releases/tag/libsmb2-6.3REFERENCE
https://www.vulncheck.com/advisories/libsmb2-before-6.3-integer-overflow-in-dce-rpc-ndr-d…ADVISORY

CVE-2026-115505

Proof-of-concept exploits (1)

CVE references

References