CVE Intelligence
Critical Memory corruption

CVE-2016-4658 — Nokogiri does not forbid namespace nodes in XPointer ranges

xpointer.c in libxml2 before 2.9.5 (as used in Apple iOS before 10, OS X before 10.12, tvOS before 10, and watchOS before 3, and other products) does not forbid namespace nodes in XPointer ranges, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free and memory corruption) via a crafted XML document.

Published Sep 25, 2016 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: apple

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 8.6% (30-day exploitation probability)+14
  • Technical severity (critical)+10

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
8.56%
ahead of 95% of scored CVEs · Oct 14, 2026
Affects
Apple
Iphone Os and 5 more
CVSS base
9.8
Critical · 2 source(s)

Remediation

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

  • Documented patch — git.gnome.org (NIST National Vulnerability Database)
  • Rubygems Nokogiri: fixed in version 1.7.1 — github.com (GitHub Security Advisories)

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Apple Iphone Os, Apple Mac Os X, Apple Tvos…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. EPSS ahead of 95% of scored CVEs: prioritize it in the patch queue.
  5. 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.

VendorProductVersionsStatusSource
Apple Iphone Os < 10.0 Vulnerable NIST National Vulnerability Database
Apple Mac Os X < 10.12 Vulnerable NIST National Vulnerability Database
Apple Tvos < 10.0 Vulnerable NIST National Vulnerability Database
Apple Watchos < 3.0 Vulnerable NIST National Vulnerability Database
Xmlsoft Libxml2 < 2.9.5 Vulnerable NIST National Vulnerability Database
Rubygems Nokogiri < 1.7.1 Vulnerable GitHub Security Advisories

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
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.

ScoreVersionSeverityExpl.ImpactScored by
9.8 CVSS 3.0 Critical 3.9 5.9 nvd@nist.gov via NIST National Vulnerability Database
9.8 CVSS 3.0 Critical — — GitHub, Inc. via GitHub Security Advisories
10.0 CVSS 2.0 High 10.0 10.0 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.0/AV:N/AC:L/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 8.56%

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
  • Fix documented
    Oct 14, 2026 · GitHub Security Advisories
  • Affected products added · rubygems/nokogiri
    Oct 14, 2026 · GitHub Security Advisories
  • Record published
    Oct 14, 2026
  • Fix documented
    Oct 14, 2026 · NIST National Vulnerability Database
  • Affected products added · apple/iphone os, apple/mac os x, apple/tvos, apple/watchos, xmlsoft/libxml2
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 9.8
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2016
  • CVE published
    Sep 25, 2016 · apple

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

16 on the record

Elsewhere on this site

Apple
every CVE for this vendor
Memory corruption
same class
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-86950 Apple Multiple Products Out-of-Bounds Write Vulnerability KEV 16d
  • CVE-2026-43731 Use After Free in Apple Safari Jun 29, 2026
  • CVE-2026-43734 Use After Free in Apple Safari Jun 29, 2026
  • CVE-2026-43732 Path Traversal in Apple Safari Jun 29, 2026
  • CVE-2026-43745 Out-of-bounds Write in Apple Safari Jun 29, 2026
  • CVE-2026-43727 Use After Free in Apple Safari Jun 29, 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 CISA SSVC assessment.
  • 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-2016-4658 is "Nokogiri does not forbid namespace nodes in XPointer ranges", rated Critical. It affects Iphone Os (Apple); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 8.56% 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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