CVE-2026-49428 json
posixshm: system calls can incorrectly free memory of largepage objects
published 2026-08-19 2 mo ago modified 2026-09-01 2 mo ago also EUVD-2026-62255
- cvss
- 8.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 27%
- public exploits
- 0
- none known
Summary
Certain system calls, such open(2) with the O_TRUNC flag set, and fspacectl(2), could incorrectly free memory in largepage objects. These operations are not permitted on largepage objects, but the implementation did not verify this.
An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.
Patch / fix
- FreeBSD FreeBSD p1, p7, p11, p16
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2 mo ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- FreeBSD FreeBSD
Classification
- Weakness
-
- CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes
References
-
security.freebsd.org
/advisories/FreeBSD-SA-26:44.posixshm.asc
vendor-advisory
Sources
- CVE List CVE-2026-49428
- NVD CVE-2026-49428
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.