Description
libsmb2 through 6.2 contains a heap out-of-bounds read vulnerability in smb2_decode_file_all_info that allows malicious SMB servers to crash clients by sending an unchecked FileNameLength. Attackers controlling the server or performing man-in-the-middle on unsigned sessions can return crafted FileAllInformation replies to smb2_stat or smb2_fstat calls, crashing the client.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| sahlberg | libsmb2 | ≤ 6.2 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libsmb2 | No fix yet | — |
| Debian 13 | libsmb2 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libsmb2 | No fix yet | — |
| Ubuntu 26.04 LTS | libsmb2 | No fix yet | — |
References
- https://hackmd.io/@haind-pwn/libsmb2-query-info-reply-oob-read technical-description exploit
- https://github.com/sahlberg/libsmb2/blob/d67e213a5c4e7e4969fd81f0b95e4ca5831fbba1/lib/smb2-data-file-info.c#L202 technical-description
- https://github.com/sahlberg/libsmb2/commit/57bee9fb941a39307145b82e4dd1718862f30a74 patch
- https://github.com/sahlberg/libsmb2 product
- VulnCheck Advisory: libsmb2 through 6.2 Heap Out-of-Bounds Read via smb2_decode_file_all_info third-party-advisory