8.4

CVE-2026-49428: posixshm: system calls can incorrectly free memory of largepage objects

Analyzed
Published 19-08-2026Last modified 20-08-2026

Vulnerability summary

CVE-2026-49428 is a high (CVSS 8.4) vulnerability in freebsd. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 27.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 8.4, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.4/10
010
High · v3.1 (CVE.org)
EPSS score
0.34%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 19-08-2026
    PublishedVulnerability first disclosed.
  2. 20-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.34% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Freebsd1 product
  • freebsdEOL≥ 15.1-RELEASE, < p1 | ≥ 15.0-RELEASE, < p11 | ≥ 14.4-RELEASE, < p7 | ≥ 14.3-RELEASE, < p16 | 14.3 | 14.3:p1 | 14.3:p10 | 14.3:p11 | 14.3:p12 | 14.3:p13 | 14.3:p14 | 14.3:p15 | 14.3:p2 | 14.3:p3 | 14.3:p4 | 14.3:p5 | 14.3:p6 | 14.3:p7 | 14.3:p8 | 14.3:p9 | 14.4 | 14.4:p1 | 14.4:p2 | 14.4:p3 | 14.4:p4 | 14.4:p5 | 14.4:p6 | 14.4:rc1 | 15.0 | 15.0:p1 | 15.0:p10 | 15.0:p2 | 15.0:p3 | 15.0:p4 | 15.0:p5 | 15.0:p6 | 15.0:p7 | 15.0:p8 | 15.0:p9 | 15.1 | 15.1:rc2 | 15.1:rc3-p1

1 vendor · 1 product

References

1 links