CVE-2026-101307: When the PCM sample array needs to grow, the RACK stack doubles a 16-bit allocation counter

This month

CRITICAL 9.1REMOTEMITIGATE

CVE-2026-101307 is a critical-severity flaw (CVSS 9.1) affecting freebsd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

When the PCM sample array needs to grow, the RACK stack doubles a 16-bit allocation counter. Repeated doublings caused the counter to wrap to zero, resulting in a near-zero-length allocation followed by a copy of the existing samples into the undersized buffer. A remote peer can trigger the expansion by sending a sufficient number of ACKs on an established connection. A remote attacker who can establish a TCP connection to a system using the R

Why this priority

Critical severity
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-122, CWE-787
Published	2026-10-15
Last modified	2026-10-20

Publisher (CNA): FreeBSD · Vendor: freebsd

Last updated 2026-10-20 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-15 07:17 UTCPublished CVE record published
2026-10-20 00:21 UTCUpdated Record last modified

freebsd freebsd MITIGATE

Affected: 15.1 · 15.1 p1 · 15.1 p2 · 15.1 p3 · 15.1 p4

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

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-2026-101307?

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

Is CVE-2026-101307 being exploited?

CVE-2026-101307 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-2026-101307 affect?

CVE-2026-101307 affects freebsd. Severity is critical (CVSS 9.1). When the PCM sample array needs to grow, the RACK stack doubles a 16-bit allocation counter. Repeated doublings caused the counter to wrap to zero, resulting in a near-zero-length allocation followed by a copy of the existing samples into

How urgent is CVE-2026-101307?

Priority 43/100. Critical severity; Remotely exploitable, no login, no user action

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References

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