9.8

CVE-2025-49709: mozilla firefox Out-of-bounds Write

CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2025-49709CGA-6jv2-hc6j-86q3CGA-hqgq-jmr9-r99x
Published 11-06-2025Last modified 27-07-2026
Open JSON

Vulnerability summary

CVE-2025-49709 is a critical (CVSS 9.8) Out-of-bounds Write vulnerability in mozilla firefox. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 51% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.66%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 4
OPENSUSE-SU-2025:15203-1OPENSUSE-SU-2026:11373-1CGA-M326-V69P-FR2XCGA-W6XM-674G-W96J

Timeline

  1. 11-06-2025
    PublishedVulnerability first disclosed.
  2. 27-07-2026
    Last modifiedVulnerability information updated.

Description

Certain canvas operations could have lead to memory corruption. This vulnerability was fixed in Firefox 139.0.4.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.66%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

0.00 pp

From 0.66% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.66%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu7 products
  • mozjs102All versions (No fix recorded)
  • mozjs115All versions (No fix recorded)
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
Chainguard2 products
  • firefox< 139.0.4-r0
  • firefox-esr< 139.0.4-r0
Mozilla1 product
Wolfi1 product
  • firefox< 139.0.4-r0

4 vendors · 11 products

References

5 links