CVE-2026-49422: The RACK setsockopt(2) handler drops the connection lock in order to copy option data from userspace, then rea

Routine

HIGH 8.4MITIGATE

CVE-2026-49422 is a high-severity flaw (CVSS 8.4) affecting freebsd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The RACK setsockopt(2) handler drops the connection lock in order to copy option data from userspace, then reacquires the lock. After reacquiring, it verifies that the TCP stack had not been switched away, but did not reload its pointer to the stack's per-connection control block. If userspace switches stacks twice during this window, the check will succeed but the saved pointer will refer to freed memory. The bug may be exploitable by an unpr

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.4 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 94%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-08-19
Last modified	2026-09-01

Publisher (CNA): FreeBSD · Vendor: freebsd

Last updated 2026-09-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-19 06:17 UTCPublished CVE record published
2026-09-01 20:20 UTCUpdated Record last modified

freebsd freebsd MITIGATE

Affected: 14.3 · 14.3 p1 · 14.3 p10 · 14.3 p11 · 14.3 p12 · 14.3 p13 · 14.3 p14 · 14.3 p15

Fixed in: no fixed release known

Safe to downgrade to: a release before 14.3

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-49422?

freebsd: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-49422 being exploited?

CVE-2026-49422 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-49422 affect?

CVE-2026-49422 affects freebsd. Severity is high (CVSS 8.4). The RACK setsockopt(2) handler drops the connection lock in order to copy option data from userspace, then reacquires the lock. After reacquiring, it verifies that the TCP stack had not been switched away, but did not reload its pointer to

How urgent is CVE-2026-49422?

Priority 31/100. High severity

Related CVEs

CVE-2026-101304 HIGH 7.1 MITIGATE When fdescfs(4) was mounted in a jail with the "nodup" option, opening /dev/fd/N returned a descriptor that di
CVE-2026-101307 CRITICAL 9.1 MITIGATE When the PCM sample array needs to grow, the RACK stack doubles a 16-bit allocation counter
CVE-2026-101306 CRITICAL 9.8 MITIGATE SCM_RIGHTS file descriptor passing did not preserve FD_RESOLVE_BENEATH when a descriptor was transferred
CVE-2026-101305 HIGH 8.8 MITIGATE renameat(2) did not enforce FD_RESOLVE_BENEATH on its directory arguments
CVE-2026-101303 HIGH 7.5 MITIGATE The IPv6 UDP send path for unconnected sockets did not apply the jail policy of rewriting a loopback destinati

References

← Back to latest CVEs