4.8

CVE-2025-4087: mozilla firefox Out-of-bounds Read

CVSS: 4.8v3.1MediumModified
AliasesUBUNTU-CVE-2025-4087DEBIAN-CVE-2025-4087CGA-7f2m-qmhj-h8f8
Published 29-04-2025Last modified 13-04-2026
Open JSON

Vulnerability summary

CVE-2025-4087 is a medium (CVSS 4.8) Out-of-bounds Read vulnerability in mozilla firefox. EPSS estimates a 0.32% chance of exploitation in the next 30 days, higher than 23.1% of scored vulnerabilities.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.32%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 34 · Related 7
DLA-4167-1DLA-4172-1DSA-5910-1DSA-5912-1MGASA-2025-0150MGASA-2025-0151

Timeline

  1. 29-04-2025
    PublishedVulnerability first disclosed.
  2. 13-04-2026
    Last modifiedVulnerability information updated.

Description

A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior due to missing null checks during attribute access. This could lead to out-of-bounds read access and potentially, memory corruption. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbird 128.10.

CVSS metrics

6 scores · 6 sources · 1 version

EPSS trend

Probability

0.32%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

+0.01 pp

From 0.30% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.32%

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

Ubuntu8 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< 128.10-r0
  • firefox-esr< 128.10-r0
Debian2 products
  • firefox-esr< 128.10.0esr-1~deb12u1 | < 128.10.0esr-1
  • thunderbird< 1:128.10.0esr-1~deb12u1 | < 1:128.10.0esr-1
Mozilla2 products
Wolfi1 product
  • firefox< 128.10-r0

5 vendors · 15 products

References

13 links
Show all 13 references