NVD / CVE Program· CNA mozilla

CVE-2022-38476: A data race could occur in the <code>PK11_ChangePW</code> function, potentially leading to a use-after-free vulnerability.

Noroxi assessment

Priority: Monitor (action score 30/100)

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: 0.85% (FIRST EPSS); higher than 58.4% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. Special conditions such as timing or configuration are required.
Fixed version: firefox (AlmaLinux:8) 91.13.0-1.el8_6.alma; thunderbird (AlmaLinux:8) 91.13.0-1.el8_6.alma; firefox (AlmaLinux:9) 91.13.0-1.el9_0.alma.

Low priority for now. Upgrade to firefox (AlmaLinux:8) 91.13.0-1.el8_6.alma; thunderbird (AlmaLinux:8) 91.13.0-1.el8_6.alma; firefox (AlmaLinux:9) 91.13.0-1.el9_0.alma 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 data race could occur in the <code>PK11_ChangePW</code> function, potentially leading to a use-after-free vulnerability. In Firefox, this lock protected the data when a user changed their master password. This vulnerability affects Firefox ESR < 102.2 and Thunderbird < 102.2.

HighCVSS 7.5 · v3.1—No exploit Fix available

Published: Dec 22, 2022
Updated: Jun 17, 2026
EPSS: 0.8% · 58th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.8%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

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

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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.

Vendor	Product	CPE
mozilla	firefox esr	cpe:2.3:a:mozilla:firefox_esr
mozilla	thunderbird	cpe:2.3:a:mozilla:thunderbird

Affected versions

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

mozilla firefox esrbefore 102.2
mozilla thunderbirdbefore 102.2

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 ESR
- unspecified and later · before 102.2affected
Mozilla Thunderbird
- unspecified and later · before 102.2affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
AlmaLinux:8	firefox	before 91.13.0-1.el8_6.alma	91.13.0-1.el8_6.alma
AlmaLinux:8	thunderbird	before 91.13.0-1.el8_6.alma	91.13.0-1.el8_6.alma
AlmaLinux:9	firefox	before 91.13.0-1.el9_0.alma	91.13.0-1.el9_0.alma
AlmaLinux:9	thunderbird	before 91.13.0-1.el9_0.alma	91.13.0-1.el9_0.alma
Debian:12	firefox-esr	before 102.2.0esr-1	102.2.0esr-1
Debian:12	thunderbird	before 1:102.2.0-1	1:102.2.0-1
openSUSE:Tumbleweed	MozillaThunderbird	before 102.2.0-1.1	102.2.0-1.1
Red Hat:enterprise_linux:7::client	firefox	before 0:91.13.0-1.el7_9	0:91.13.0-1.el7_9
Red Hat:enterprise_linux:7::client	firefox-debuginfo	before 0:91.13.0-1.el7_9	0:91.13.0-1.el7_9
Red Hat:enterprise_linux:7::client	thunderbird	before 0:91.13.0-1.el7_9	0:91.13.0-1.el7_9
Red Hat:enterprise_linux:7::client	thunderbird-debuginfo	before 0:91.13.0-1.el7_9	0:91.13.0-1.el7_9
Red Hat:enterprise_linux:8::appstream	firefox	before 0:91.13.0-1.el8_6	0:91.13.0-1.el8_6
Red Hat:enterprise_linux:8::appstream	firefox-debuginfo	before 0:91.13.0-1.el8_6	0:91.13.0-1.el8_6
Red Hat:enterprise_linux:8::appstream	firefox-debugsource	before 0:91.13.0-1.el8_6	0:91.13.0-1.el8_6
Red Hat:enterprise_linux:8::appstream	thunderbird	before 0:91.13.0-1.el8_6	0:91.13.0-1.el8_6
Red Hat:enterprise_linux:8::appstream	thunderbird-debuginfo	before 0:91.13.0-1.el8_6	0:91.13.0-1.el8_6
Red Hat:enterprise_linux:8::appstream	thunderbird-debugsource	before 0:91.13.0-1.el8_6	0:91.13.0-1.el8_6
Red Hat:enterprise_linux:9::appstream	firefox	before 0:91.13.0-1.el9_0	0:91.13.0-1.el9_0
Red Hat:enterprise_linux:9::appstream	firefox-debuginfo	before 0:91.13.0-1.el9_0	0:91.13.0-1.el9_0
Red Hat:enterprise_linux:9::appstream	firefox-debugsource	before 0:91.13.0-1.el9_0	0:91.13.0-1.el9_0
Red Hat:enterprise_linux:9::appstream	thunderbird	before 0:91.13.0-1.el9_0	0:91.13.0-1.el9_0
Red Hat:enterprise_linux:9::appstream	thunderbird-debuginfo	before 0:91.13.0-1.el9_0	0:91.13.0-1.el9_0
Red Hat:enterprise_linux:9::appstream	thunderbird-debugsource	before 0:91.13.0-1.el9_0	0:91.13.0-1.el9_0
Red Hat:rhel_e4s:8.1::appstream	firefox	before 0:91.13.0-1.el8_1	0:91.13.0-1.el8_1

+19

Same product

mozilla: all records

Other highest-scoring records for the same primary product.

CVE-2021-4127An out of date graphics library (Angle) likely contained vulnerabilities that could potentially be exploited.
39Monitor
CVE-2023-6862A use-after-free was identified in the `nsDNSService::Init`.
35Monitor
CVE-2023-25746Memory safety bugs present in Firefox ESR 102.7.
35Monitor

Published before and after this one in the same product

← EarlierCVE-2021-38495Nov 2, 2021 · Mozilla developers reported memory safety bugs present in Thunderbird 78.13.0.
35Monitor
← EarlierCVE-2022-1196Dec 22, 2022 · After a VR Process is destroyed, a reference to it may have been retained and used, leading to a use-after-free and potentially exploitable
26Monitor
Later →CVE-2023-1945Jun 2, 2023 · Unexpected data returned from the Safe Browsing API could have led to memory corruption and a potentially exploitable crash.
26Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
almalinux:firefox	91.13.0-1.el9_0.alma · AlmaLinux:9	Package registry (OSV)
almalinux:thunderbird	91.13.0-1.el8_6.alma · AlmaLinux:8	Package registry (OSV)
debian:firefox-esr	102.2.0esr-1 · Debian:12	Package registry (OSV)
debian:thunderbird	1:102.2.0-1 · Debian:12	Package registry (OSV)
opensuse:MozillaThunderbird	102.2.0-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
red hat:firefox	0:91.13.0-1.el9_0 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:firefox-debuginfo	0:91.13.0-1.el9_0 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:firefox-debugsource	0:91.13.0-1.el9_0 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:thunderbird	0:91.13.0-1.el8_6 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:thunderbird-debuginfo	0:91.13.0-1.el8_6 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:thunderbird-debugsource	0:91.13.0-1.el8_6 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
rocky linux:firefox	0:91.13.0-1.el8_6 · Rocky Linux:8	Package registry (OSV)
rocky linux:thunderbird	0:91.13.0-1.el8_6 · Rocky Linux:8	Package 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.

No history yet (it accumulates with the daily EPSS job).

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.
A user must open a link or visit a page.
Special conditions such as timing or configuration are required.

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: High
Privileges required: None
User interaction: Required
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/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

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&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

Fix✗ → ✓Sep 28, 2026, 10:47 PM UTC

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

References

bugzilla.mozilla.org/show_bug.cgi?id=1760998

Show all references (2 more)

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

All records