- Exploited
- No known exploitation
- Fix
- Fixed in 6.18.61, 7.3.2
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 6.18.61, 7.3.2.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 20/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The Linux kernel's ksmbd SMB file server can write two bytes past the end of a response buffer when it builds file stream information, because the space for the UTF-16 string terminator was not reserved. The fix reserves that space, and the reported lengths stay the same.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: reserve space for the UTF-16 terminator in stream info
smb_strtoUTF16() always writes a terminating zero UTF-16 unit after the converted characters, but get_file_stream_info() budgets only sizeof(struct smb2_file_stream_info) + streamlen * 2 for a stream entry and sizeof(struct smb2_file_stream_info) + 7 * 2 for the trailing "::$DATA" entry. When an entry exactly fills the 448-byte small response buffer, the terminator is written two bytes past the allocation.
Reserve one extra UTF-16 unit in both budget checks. The terminator is not part of the wire format, so the reported lengths are unchanged.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach20/20Affects Linux kernel (software on nearly every server, desktop or phone)
- Severity?/10Unknown. No CVSS score or vendor rating
- No patch0/5No signal
What would change the score
- Would score about 75 if added to CISA KEV
- Would score about 70 if CISA's SSVC rates exploitation active
- Would score about 42 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 6.18.61, 7.3.2.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- Linux Linux
fixed in 6.18.61; fixed in 7.3.2
- Linux Linux
Version range not reported
Evidence 3
- Link
- Link
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-99273
Is CVE-2026-99273 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-99273?
Linux: before 6.18.61; before 7.3.2.Source: cve.now feed data
How do I fix CVE-2026-99273?
Upgrade to a fixed version: 6.18.61, 7.3.2.Source: cve.now feed data