🛡️ CVE-2025-8033 on Debian — firefox-esr

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Distribution advisory

This page covers CVE-2025-8033 as tracked by Debian, for the package firefox-esr. The fix is available in version 128.13.0esr-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability none.

Weakness class

DEBIAN-CVE-2025-8033 is classified as CWE-476: NULL Pointer Dereference. A pointer that can be null is used without a check, crashing the process.

Affected software

DEBIAN-CVE-2025-8033 is recorded against 2 packages.

  • firefox-esr (fixed in 128.13.0esr-1)
  • thunderbird (fixed in 1:128.13.0esr-1)

Timeline and source

Published on 22 July 2025 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2025-8033 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2025-07-22
Updated 2026-08-12
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
firefox-esr — 128.13.0esr-1
thunderbird — 1:128.13.0esr-1

Similar Threats

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