libsmb2 Heap Out-of-Bounds Read via File System Info Decoders
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.
Summary
libsmb2 through 6.2 contains a heap out-of-bounds read in smb2_decode_file_fs_volume_info and smb2_decode_file_fs_attribute_info. A malicious SMB server, or an attacker who can intercept unsigned sessions, can send crafted QUERY_INFO replies with missing or oversized name lengths, which makes the client read past its reply buffers and crash. The flaw is tracked as CWE-125. A public exploit is linked in the references, and CISA's SSVC data rates it as proof-of-concept only.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
libsmb2 through 6.2 contains a heap out-of-bounds read vulnerability in smb2_decode_file_fs_volume_info and smb2_decode_file_fs_attribute_info that allows malicious SMB servers to read past reply buffers. Attackers controlling a server or intercepting unsigned sessions can send crafted QUERY_INFO replies with missing or oversized name lengths to crash the client.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
The sources list no fixed version for libsmb2.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Timeline
- 2026-10-14 Threatist record created from CVE-2026-110713
- 2026-10-15 Alias added: GHSA-w2j6-hg6c-f9mp
- 2026-10-15 CISA SSVC decision points changed
References
More sahlberg vulnerabilities
- TI-2026-79487 Integer overflow in libsmb2 DCE/RPC NDR decoder lets servers corrupt heap CVSS 4.0HIGH 7.2
- TI-2026-74155 Integer underflow in libsmb2 decode_acl causes heap over-read CVSS 4.0HIGH 7.1
- TI-2026-74153 Heap out-of-bounds read in libsmb2 lets SMB servers crash clients CVSS 4.0HIGH 7.1
- TI-2026-41697 Integer underflow in sahlberg libnfs CVSS 3.1HIGH 7.1
- TI-2026-38717 libnfs through 6.0.2 before 55c18ea does not validate a string size, leading to an… CVSS 3.1HIGH 7.1
- TI-2026-70831 Out-of-bounds write in libnfs ZDR decoding CVSS 3.1HIGH 7.1
Sources
- CVE-2026-110713 · CVE Program
- CVE-2026-110713 · NVD
- FIRST EPSS
- GHSA-w2j6-hg6c-f9mp · GitHub Advisory Database · CC BY 4.0
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