High Memory corruption

CVE-2016-4472 — Buffer Errors (Improper Restriction of Operations within Memory Bounds) in Canonical Ubuntu Linux

The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via crafted XML data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-1283 and CVE-2015-2716.

Published Jun 30, 2016 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 11.9% (30-day exploitation probability)+14
Technical severity (high)+6
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

11.95%

ahead of 96% of scored CVEs · Oct 14, 2026

Affects

Canonical

Ubuntu Linux and 3 more

CVSS base

8.1

High · 1 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — bugzilla.redhat.com (NIST National Vulnerability Database)
Documented patch — sourceforge.net (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Canonical Ubuntu Linux, Libexpat Project Libexpat, Mcafee Policy Auditor…).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
EPSS ahead of 96% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Canonical	Ubuntu Linux	version 12.04	Vulnerable	NIST National Vulnerability Database
Libexpat Project	Libexpat	≤ 2.1.1	Vulnerable	NIST National Vulnerability Database
Mcafee	Policy Auditor	< 6.5.1	Vulnerable	NIST National Vulnerability Database
Python	Python	≥ 2.7.0 and < 2.7.15≥ 3.3.0 and < 3.3.7≥ 3.4.0 and < 3.4.7≥ 3.5.0 and < 3.5.4≥ 3.6.0 and < 3.6.2	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.1	CVSS 3.1	High	2.2	5.9	nvd@nist.gov via NIST National Vulnerability Database
6.8	CVSS 2.0	Medium	8.6	6.4	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 11.95%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 8.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Modified
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2016
CVE published
Jun 30, 2016 · redhat

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

7 on the record

sourceforge.net/p/expat/code_git/ci/f0bec73b018caa07d3e75ec8dd967f3785d71bde
Patch, Third Party Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
bugzilla.redhat.com/show_bug.cgi
Issue Tracking, Patch, Third Party Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
www.ubuntu.com/usn/USN-3013-1
Third Party Advisory, vendor-advisory, x_refsource_UBUNTU, NIST National Vulnerability Database
security.gentoo.org/glsa/201701-21
Third Party Advisory, vendor-advisory, x_refsource_GENTOO, NIST National Vulnerability Database
www.tenable.com/security/tns-2016-20
Third Party Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
www.securityfocus.com/bid/91528
Third Party Advisory, VDB Entry, vdb-entry, x_refsource_BID, NIST National Vulnerability Database
kc.mcafee.com/corporate/index
Third Party Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

Canonical
every CVE for this vendor

Memory corruption
same class

CWE-119
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-4360 Tarfile.extract() doesn't fully respect filter parameter Jun 30, 2026
Medium CVE-2026-0864 Configuration Injection via Carriage Return (\r) in write() method Jun 23, 2026
Medium CVE-2026-56411 Integer Overflow or Wraparound in Libexpat Project Libexpat Jun 21, 2026
Medium CVE-2026-56412 Use After Free in Libexpat Project Libexpat Jun 21, 2026
Medium CVE-2026-56410 Integer Overflow or Wraparound in Libexpat Project Libexpat Jun 21, 2026
Medium CVE-2026-56408 Integer Overflow or Wraparound in Libexpat Project Libexpat Jun 21, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2016-4472 is "Buffer Errors (Improper Restriction of Operations within Memory Bounds) in Canonical Ubuntu Linux", rated High. It affects Ubuntu Linux (Canonical); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 11.95% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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