Distribution advisory
This page covers CVE-2025-1936 as tracked by Debian, for the package firefox-esr. The fix is available in version 128.8.0esr-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. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity low, availability low.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: None — an unauthenticated stranger can try it.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
- Integrity impact: Low — limited, and the attacker does not choose what is affected.
- Availability impact: Low — limited, and the attacker does not choose what is affected.
Weakness class
DEBIAN-CVE-2025-1936 is classified as CWE-158: Improper Neutralization of Null Byte or NUL Character. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component.
Affected software
DEBIAN-CVE-2025-1936 is recorded against 2 packages.
- firefox-esr (fixed in 128.8.0esr-1)
- thunderbird (fixed in 1:128.8.0esr-1)
Timeline and source
Published on 4 March 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)
Other advisories for this package
firefox-esr has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-158: Improper Neutralization of Null Byte or NUL Character) in other software:
