What is CVE-2016-1981?

CVE-2016-1981 is a medium-severity vulnerability in Qemu, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.5/10. Published 2016-12-29.

How severe is CVE-2016-1981?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Qemu

CVE-2016-1981

QEMU (aka Quick Emulator) built with the e1000 NIC emulation support is vulnerable to an infinite loop issue. It could occur while processing data via transmit or receive descriptors, provided the initial receive/transmit descriptor head (TDH/RDH) is set outside the allocated descriptor buffer. A privileged user inside guest could use this flaw to crash the QEMU instance resulting in DoS.

Published 2016-12-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Qemu
Debian Linux — versions 7.0, 8.0

Weakness classification (CWE)

CWE-835 — Loop with Unreachable Exit Condition (Infinite Loop)

References

lists.gnu.org/archive/html/qemu-devel/2016-01/msg03454.html (Vendor Advisory, mailing-list, Patch)
security.gentoo.org/glsa/201604-01 (vendor-advisory, Third Party Advisory)
www.debian.org/security/2016/dsa-3469 (vendor-advisory, Third Party Advisory)
www.debian.org/security/2016/dsa-3470 (vendor-advisory, Third Party Advisory)
www.openwall.com/lists/oss-security/2016/01/19/10 (mailing-list, Mailing List, Third Party Advisory)
bugzilla.redhat.com/show_bug.cgi (Issue Tracking)
www.openwall.com/lists/oss-security/2016/01/22/1 (mailing-list, Mailing List, Third Party Advisory)
rhn.redhat.com/errata/RHSA-2016-2585.html (vendor-advisory, Third Party Advisory)
www.debian.org/security/2016/dsa-3471 (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/81549 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2016-1981?: CVE-2016-1981 is a medium-severity vulnerability in Qemu, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.5/10. Published 2016-12-29.
How severe is CVE-2016-1981?: Medium severity. CVSS v3 base score is 5.5 out of 10.