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NVD / CVE Program· CNA mozilla

CVE-2025-9187: Memory safety bugs fixed in Firefox 142 and Thunderbird 142

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.48% (FIRST EPSS).
  • 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: mozilla-nss (openSUSE:Leap 15.6) 3.112.2-150400.3.60.1; MozillaFirefox (openSUSE:Leap 15.6) 140.2.0-150200.152.198.1; MozillaFirefox (openSUSE:Tumbleweed) 142.0.1-1.1.

Low priority for now. Upgrade to mozilla-nss (openSUSE:Leap 15.6) 3.112.2-150400.3.60.1; MozillaFirefox (openSUSE:Leap 15.6) 140.2.0-150200.152.198.1; MozillaFirefox (openSUSE:Tumbleweed) 142.0.1-1.1 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

Memory safety bugs present in Firefox 141 and Thunderbird 141. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 142 and Thunderbird 142.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 19, 2025
Updated
Sep 30, 2026
EPSS
0.4% · 41th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
9.8
CNA · mozilla
9.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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-2025-9187

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
mozillafirefox
mozillathunderbird

Affected versions

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

  • mozilla firefoxbefore 142.0
  • mozilla thunderbirdbefore 142.0

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

    • 142 and laternot affected · rpm

  • Mozilla Thunderbird

    • 142 and laternot affected · rpm

Package-level exposure

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

EcosystemPackageAffected rangeFix
openSUSE:Leap 15.6mozilla-nssbefore 3.112.2-150400.3.60.13.112.2-150400.3.60.1
openSUSE:Leap 15.6MozillaFirefoxbefore 140.2.0-150200.152.198.1140.2.0-150200.152.198.1
openSUSE:TumbleweedMozillaFirefoxbefore 142.0.1-1.1142.0.1-1.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSmozilla-nssbefore 3.112.2-150000.3.132.13.112.2-150000.3.132.1
SUSE:Linux Enterprise Micro 5.3mozilla-nssbefore 3.112.2-150400.3.60.13.112.2-150400.3.60.1
SUSE:Linux Enterprise Module for Desktop Applications 15 SP6MozillaFirefoxbefore 140.2.0-150200.152.198.1140.2.0-150200.152.198.1
SUSE:Linux Enterprise Server 12 SP5-LTSSmozilla-nssbefore 3.112.2-58.133.13.112.2-58.133.1
SUSE:Linux Enterprise Server 12 SP5-LTSSMozillaFirefoxbefore 140.2.0-112.276.1140.2.0-112.276.1

Same product

mozilla: all records

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

Published before and after this one in the same product

  • ← EarlierCVE-2025-9185Aug 19, 2025 · Memory safety bugs fixed in Firefox ESR 115.27, Firefox ESR 128.14, Thunderbird ESR 128.14, Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbir
    32Monitor
  • ← EarlierCVE-2025-9186Aug 19, 2025 · Spoofing issue in the Address Bar component of Firefox Focus for Android
    26Monitor
  • Later →CVE-2025-10527Sep 16, 2025 · Sandbox escape due to use-after-free in the Graphics: Canvas2D component
    28Monitor

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
opensuse:mozilla-nss3.112.2-150400.3.60.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:MozillaFirefox140.2.0-150200.152.198.1 · openSUSE:Leap 15.6Package registry (OSV)
suse:mozilla-nss3.112.2-150400.3.60.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)
suse:mozilla-nss3.112.2-58.133.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:MozillaFirefox140.2.0-150200.152.198.1 · SUSE:Linux Enterprise Module for Desktop Applications 15 SP6Package 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.

Variant candidates

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

  • CVE-2026-2776189 days apartSandbox escape due to incorrect boundary conditions in the Telemetry component in External Software
    40Plan
  • CVE-2026-2778189 days apartSandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component
    40Plan
  • CVE-2026-16367336 days apartSandbox escape due to invalid pointer in the Disability Access APIs component
    40Plan
  • CVE-2025-91790 days apartSandbox escape due to invalid pointer in the Audio/Video: GMP component
    39Monitor
  • CVE-2025-804428 days apartMemory safety bugs fixed in Firefox 141 and Thunderbird 141
    39Monitor
  • CVE-2025-1172156 days apartMemory safety bug fixed in Firefox 144 and Thunderbird 144
    39Monitor

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-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (2 more)

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

All records