vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2025-1931

Use-after-free in WebTransportChild

HIGH
7.5
CVSS Score
Published: March 4, 2025 at 01:31 PM UTC
Updated: October 5, 2026 at 03:10 PM UTC
2 products affected across 1 vendorFirefoxThunderbird

Using Firefox by Mozilla?

Get instant alerts when new vulnerabilities affect Firefox - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

It was possible to cause a use-after-free in the content process side of a WebTransport connection, leading to a potentially exploitable crash. This vulnerability affects Firefox < 136, Firefox ESR < 115.21, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Firefox· Mozilla
95%
v < 115.21.0v < 136.0116.0 ≤ v < 128.8.0
Vendor states this is fixed in 115.21 (unaffected)
Affected range stops below 115.21.0, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 128.8 (unaffected)
Affected range stops below 128.8.0, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 136 (unaffected)
Affected range stops below 136.0, so it looks safe — our inference, not a vendor statement
Thunderbird· Mozilla
95%
v < 128.8.0129.0 ≤ v < 136.0
Vendor states this is fixed in 128.8 (unaffected)
Affected range stops below 128.8.0, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 136 (unaffected)
Affected range stops below 136.0, so it looks safe — our inference, not a vendor statement

References (7)

Issue Tracking
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1944126
Vendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2025-14/
Vendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2025-15/
Vendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2025-16/
Vendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2025-17/
Vendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2025-18/
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/03/msg00006.html

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-416

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card