6.5

CVE-2025-8033: mozilla firefox NULL Pointer Dereference

CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-8033DEBIAN-CVE-2025-8033CGA-528g-jjxp-jw9v
Published 22-07-2025Last modified 29-07-2026

Vulnerability summary

CVE-2025-8033 is a medium (CVSS 6.5) NULL Pointer Dereference vulnerability in mozilla firefox. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.9% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.40%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 37 · Related 12

Timeline

  1. 22-07-2025
    PublishedVulnerability first disclosed.
  2. 29-07-2026
    Last modifiedVulnerability information updated.

Description

The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

CVSS metrics

6 scores · 6 sources · 1 version

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

+0.04 pp

From 0.36% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.40%

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< 128.13-r0
  • firefox-esr< 140.1-r0
Debian2 products
  • firefox-esr< 128.13.0esr-1~deb12u1 | < 128.13.0esr-1
  • thunderbird< 1:128.13.0esr-1~deb12u1 | < 1:128.13.0esr-1
Mozilla2 products
  • firefox< 115.26.0 | < 141.0 | ≥ 128.0, < 128.13.0 | ≥ 140.0, < 140.1.0
  • thunderbird< 128.13.0 | < 141.0 | ≥ 140.0, < 140.1.0
Wolfi1 product
  • firefox< 128.13-r0

5 vendors · 15 products

References

16 links
Show all 16 references