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CVE-2018-5104· NVD / CVE Program· CNA mozilla

A use-after-free vulnerability can occur during font face manipulation when a font face is freed while still in use, resulting in a potentia

Noroxi assessment

Priority: Plan (action score 41/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 7% (FIRST EPSS); higher than 94.1% of all records.
  • 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.
  • Fixed version: firefox-esr (Debian:12) 52.6.0esr-1; thunderbird (Debian:12) 1:52.6.0-1; firefox-esr (Debian:7) 52.6.0esr-1~deb7u1.

Add it to your regular patch cycle. Upgrade to firefox-esr (Debian:12) 52.6.0esr-1; thunderbird (Debian:12) 1:52.6.0-1; firefox-esr (Debian:7) 52.6.0esr-1~deb7u1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A use-after-free vulnerability can occur during font face manipulation when a font face is freed while still in use, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.

CriticalCVSS 9.8 · v3.0—No exploit Fix available
Published
Jun 11, 2018
Updated
Jun 16, 2026
EPSS
7.0% · 94th percentile

Report tools

JSON

Action score

41

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 7.0%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2018-5104

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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

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 linux17.10
  • debian debian linux7.0
  • debian debian linux8.0
  • debian debian linux9.0
  • mozilla firefoxbefore 58.0
  • mozilla firefoxbefore 52.6.0
  • mozilla thunderbirdbefore 52.6.0
  • redhat enterprise linux desktop6.0
  • redhat enterprise linux desktop7.0
  • redhat enterprise linux server6.0
  • redhat enterprise linux server7.0
  • redhat enterprise linux server aus7.4
  • redhat enterprise linux server eus7.4
  • redhat enterprise linux server eus7.5
  • redhat enterprise linux workstation6.0
  • redhat enterprise linux workstation7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (mozilla). Independent of NVD's CPE analysis and usually ahead of it.

  • Mozilla Firefox

    • unspecified and later · before 58affected

  • Mozilla Firefox ESR

    • unspecified and later · before 52.6affected

  • Mozilla Thunderbird

    • unspecified and later · before 52.6affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12firefox-esrbefore 52.6.0esr-152.6.0esr-1
Debian:12thunderbirdbefore 1:52.6.0-11:52.6.0-1
Debian:7firefox-esrbefore 52.6.0esr-1~deb7u152.6.0esr-1~deb7u1
Debian:7thunderbirdbefore 1:52.6.0-1~deb7u11:52.6.0-1~deb7u1
Debian:8firefox-esrbefore 52.6.0esr-1~deb8u152.6.0esr-1~deb8u1
Debian:8thunderbirdbefore 1:52.6.0-1~deb8u11:52.6.0-1~deb8u1
Debian:9firefox-esrbefore 52.6.0esr-1~deb9u152.6.0esr-1~deb9u1
Debian:9thunderbirdbefore 1:52.6.0-1~deb9u11:52.6.0-1~deb9u1
Red Hat:enterprise_linux:6::clientfirefoxbefore 0:52.6.0-1.el6_90:52.6.0-1.el6_9
Red Hat:enterprise_linux:6::clientfirefox-debuginfobefore 0:52.6.0-1.el6_90:52.6.0-1.el6_9
Red Hat:enterprise_linux:6::clientthunderbirdbefore 0:52.6.0-1.el6_90:52.6.0-1.el6_9
Red Hat:enterprise_linux:6::clientthunderbird-debuginfobefore 0:52.6.0-1.el6_90:52.6.0-1.el6_9
Red Hat:enterprise_linux:7::clientfirefoxbefore 0:52.6.0-1.el7_40:52.6.0-1.el7_4
Red Hat:enterprise_linux:7::clientfirefox-debuginfobefore 0:52.6.0-1.el7_40:52.6.0-1.el7_4
Red Hat:enterprise_linux:7::clientthunderbirdbefore 0:52.6.0-1.el7_40:52.6.0-1.el7_4
Red Hat:enterprise_linux:7::clientthunderbird-debuginfobefore 0:52.6.0-1.el7_40:52.6.0-1.el7_4
SUSE:Linux Enterprise Software Development Kit 11 SP4MozillaFirefoxbefore 52.6.0esr-72.20.252.6.0esr-72.20.2
SUSE:OpenStack Cloud 6MozillaFirefoxbefore 52.6.0esr-109.13.152.6.0esr-109.13.1
SUSE:Package Hub 12MozillaThunderbirdbefore 52.6-54.152.6-54.1

Same product

debian: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-9079A use-after-free vulnerability in SVG Animation has been discovered.KEV
    86Now
  • CVE-2024-44308The issue was addressed with improved checks.KEV
    68This week
  • CVE-2021-25216A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack
    64This week

Published before and after this one in the same product

  • ← EarlierCVE-2018-5102Jun 11, 2018 · A use-after-free vulnerability can occur when manipulating HTML media elements with media streams, resulting in a potentially exploitable cr
    41Plan
  • ← EarlierCVE-2018-5103Jun 11, 2018 · A use-after-free vulnerability can occur during mouse event handling due to issues with multiprocess support.
    40Plan
  • Later →CVE-2018-5117Jun 11, 2018 · If right-to-left text is used in the addressbar with left-to-right alignment, it is possible in some circumstances to scroll this text to sp
    22Monitor

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-esr52.6.0esr-1 · Debian:12Package registry (OSV)
debian:thunderbird1:52.6.0-1 · Debian:12Package registry (OSV)
red hat:firefox0:52.6.0-1.el6_9 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:firefox-debuginfo0:52.6.0-1.el6_9 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:thunderbird0:52.6.0-1.el6_9 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
red hat:thunderbird-debuginfo0:52.6.0-1.el6_9 · Red Hat:enterprise_linux:6::clientPackage registry (OSV)
suse:MozillaFirefox52.6.0esr-72.20.2 · SUSE:Linux Enterprise Software Development Kit 11 SP4Package registry (OSV)
suse:MozillaThunderbird52.6-54.1 · SUSE:Package Hub 12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

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.

Credits

All researchers

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.

The bug in code

The whole CWE-416 class

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

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records