CVE-2026-49428: posixshm: system calls can incorrectly free memory of largepage objects
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.3%
EPSS score, percentile 27.6 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 8.4 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- from 15.1-RELEASE to before p1
- from 15.0-RELEASE to before p11
- from 14.4-RELEASE to before p7
- from 14.3-RELEASE to before p16
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 15.1-RELEASE to before p1 |
| Affected | from 15.0-RELEASE to before p11 |
| Affected | from 14.4-RELEASE to before p7 |
| Affected | from 14.3-RELEASE to before p16 |
Versions not listed are: unknown.
Source: CVE List, as of . About the data.
About this vulnerability
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.
Summary: CVE record, as of .
- CISA has not added CVE-2026-49428 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 19 Aug 2026.
- The CVE record carries a CVSS v3.1 base score of 8.4 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 27.6), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.
- The credits in the CVE record name OpenAI as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
posixshm: system calls can incorrectly free memory of largepage objects
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.
Source: CVE List, as of . About the data.
Weakness
CWE-915
- CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |