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CVE-2025-1938

Memory safety bugs fixed in Firefox 136, Thunderbird 136, Firefox ESR 128.8, and Thunderbird 128.8

No known exploitation. EPSS puts it in the 26th percentile. Fixed versions are out.

CVSS 3.16.5MediumEPSS percentile26th0.3% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFix5 products2 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Mozilla FirefoxFixed builds128.8, 136Stated by: CVE record
  • Mozilla ThunderbirdFixed builds128.8, 136Stated by: CVE record
  • Red Hat Inc. Red Hat Enterprise LinuxAffected: 7Upgrade to: not statedStated by: BDU
  • Canonical Ltd. UbuntuAffected: 20.04 LTSUpgrade to: not statedStated by: BDU
  • Сообщество свободного программного обеспечения Debian GNU/LinuxAffected: 11Upgrade to: not statedStated by: BDU

Versions as the sources state them. 5 more products have version data. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7. 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 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS26th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.3% chance of exploitation activity in the next 30 days, which ranks it in the 26th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

10 events over 580 days, from the signal feeds we watch.

  1. Patch availablerecord updated
  2. Patch availablerecord updated
  3. OpenVAS check added
  4. Patch availablerecord updated
  5. Publishedweakness classified, att&ck mapped

Affected products

And 7 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 6.5 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality LowSome restricted information is disclosed, but limited in scope
  • Integrity LowData modification is possible but limited in scope or consequence
  • Availability NoneNo availability impact

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 18 more references. See all after sign-in

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We'll flag the next CVE, public exploit or patch for Firefox ESR, not every advisory.