Buffer overflow in Red Hat Enterprise Linux 10

CVE-2026-120831

A flaw was found in libslirp in if_output(). When moving a session from the fast queue to the batch queue, the code unlinked and reinserted an arbitrary packet via ifm->m_nextpkt instead of the session queue head, corrupting queue pointers. A guest generating burst traffic could crash the host networking process, causing a denial of service.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-120831?
CVE-2026-120831 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Out-of-bounds Write. CVSS score: 6.5/10. Published 2026-11-03.
How severe is CVE-2026-120831?
Medium severity. CVSS v3 base score is 6.5 out of 10.