Skip to content
Noroxi
CVE-2018-18500· NVD / CVE Program· CNA mozilla

A use-after-free vulnerability can occur while parsing an HTML5 stream in concert with custom HTML elements.

A use-after-free vulnerability can occur while parsing an HTML5 stream in concert with custom HTML elements. This results in the stream parser object being freed while still in use, leading to a potentially exploitable crash. This vulnerability affects Thunderbird < 60.5, Firefox ESR < 60.5, and Firefox < 65.

CriticalCVSS 9.8 · v3.0—Proof of concept Fix available

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help
Published
Feb 5, 2019
Updated
Jun 16, 2026
EPSS
12.7% · 96th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

43

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
4 / 30 · 12.7%

Affected systems

VendorProduct
mozillafirefox
mozillafirefox esr
mozillathunderbird
canonicalubuntu linux
debiandebian linux
redhatenterprise linux desktop
redhatenterprise linux server
redhatenterprise linux server aus
redhatenterprise linux server eus
redhatenterprise linux server tus
redhatenterprise linux workstation

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux14.04
  • canonical ubuntu linux16.04
  • canonical ubuntu linux18.04
  • canonical ubuntu linux18.10
  • debian debian linux8.0
  • debian debian linux9.0
  • mozilla firefoxbefore 65.0
  • mozilla firefox esrbefore 60.5
  • mozilla thunderbirdbefore 60.5
  • redhat enterprise linux desktop6.0
  • redhat enterprise linux desktop7.0
  • redhat enterprise linux server6.0
  • redhat enterprise linux server7.0
  • redhat enterprise linux server aus7.6
  • redhat enterprise linux server eus7.6
  • redhat enterprise linux server tus7.6
  • redhat enterprise linux workstation6.0
  • redhat enterprise linux workstation7.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12firefox-esrbefore 60.5.0esr-160.5.0esr-1
Debian:12thunderbirdbefore 1:60.5.0-11:60.5.0-1
Debian:8firefox-esrbefore 60.5.0esr-1~deb8u160.5.0esr-1~deb8u1
Debian:8thunderbirdbefore 1:60.5.1-1~deb8u11:60.5.1-1~deb8u1
Debian:9firefox-esrbefore 60.5.0esr-1~deb9u160.5.0esr-1~deb9u1
Debian:9thunderbirdbefore 1:60.5.1-1~deb9u11:60.5.1-1~deb9u1
openSUSE:Leap 15.0mozilla-nssbefore 3.41.1-lp150.2.20.13.41.1-lp150.2.20.1
openSUSE:Leap 15.0MozillaFirefoxbefore 60.8.0-lp150.3.62.160.8.0-lp150.3.62.1
Red Hat:enterprise_linux:6::clientfirefoxbefore 0:60.5.0-2.el60:60.5.0-2.el6
Red Hat:enterprise_linux:6::clientfirefox-debuginfobefore 0:60.5.0-2.el60:60.5.0-2.el6
Red Hat:enterprise_linux:6::clientthunderbirdbefore 0:60.5.0-1.el6_100:60.5.0-1.el6_10
Red Hat:enterprise_linux:6::clientthunderbird-debuginfobefore 0:60.5.0-1.el6_100:60.5.0-1.el6_10
Red Hat:enterprise_linux:7::clientfirefoxbefore 0:60.5.0-2.el70:60.5.0-2.el7
Red Hat:enterprise_linux:7::clientfirefox-debuginfobefore 0:60.5.0-2.el70:60.5.0-2.el7
Red Hat:enterprise_linux:7::clientthunderbirdbefore 0:60.5.0-1.el7_60:60.5.0-1.el7_6
Red Hat:enterprise_linux:7::clientthunderbird-debuginfobefore 0:60.5.0-1.el7_60:60.5.0-1.el7_6
SUSE:Linux Enterprise Module for Basesystem 15mozilla-nssbefore 3.41.1-3.13.13.41.1-3.13.1
SUSE:Linux Enterprise Module for Desktop Applications 15MozillaFirefoxbefore 60.5.0-3.24.260.5.0-3.24.2
SUSE:Linux Enterprise Workstation Extension 15MozillaThunderbirdbefore 60.5.0-3.20.260.5.0-3.20.2
SUSE:OpenStack Cloud 7mozilla-nssbefore 3.41.1-58.25.13.41.1-58.25.1
SUSE:OpenStack Cloud 7MozillaFirefoxbefore 60.5.0esr-109.58.360.5.0esr-109.58.3
SUSE:OpenStack Cloud 7MozillaFirefox-branding-SLEbefore 60-32.5.160-32.5.1
SUSE:Package Hub 12MozillaThunderbirdbefore 60.5.1-79.160.5.1-79.1

Other highest-scoring records for the same primary product.

  • CVE-2010-3765Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before 3.1.6 and 3.0.x before 3.0.10, and SeaMonkey 2.x befKEV
    94Now
  • CVE-2019-11708Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxeKEV
    87Now
  • CVE-2015-4495The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote attackers to bypassKEV
    86Now
  • CVE-2013-1690Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before 17.0.7 do not properKEV
    86Now
  • CVE-2019-17026Incorrect alias information in IonMonkey JIT compiler for setting array elements could lead to a type confusion.KEV
    79This week
  • CVE-2024-9680An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines.KEV
    76This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:firefox-esr60.5.0esr-1 · Debian:12Package registry (OSV)
debian:thunderbird1:60.5.0-1 · Debian:12Package registry (OSV)
opensuse:mozilla-nss3.41.1-lp150.2.20.1 · openSUSE:Leap 15.0Package registry (OSV)
opensuse:MozillaFirefox60.8.0-lp150.3.62.1 · openSUSE:Leap 15.0Package registry (OSV)
red hat:firefox0:60.5.0-2.el6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:firefox-debuginfo0:60.5.0-2.el6 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:thunderbird0:60.5.0-1.el6_10 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:thunderbird-debuginfo0:60.5.0-1.el6_10 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
suse:mozilla-nss3.41.1-3.13.1 · SUSE:Linux Enterprise Module for Basesystem 15Package registry (OSV)
suse:MozillaFirefox60.5.0-3.24.2 · SUSE:Linux Enterprise Module for Desktop Applications 15Package registry (OSV)
suse:MozillaFirefox-branding-SLE60-32.5.1 · SUSE:OpenStack Cloud 7Package registry (OSV)
suse:MozillaThunderbird60.5.0-3.20.2 · SUSE:Linux Enterprise Workstation Extension 15Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:612019-04-18

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+71 d
  3. TodaySep 30, 2026+2794 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

All records