🛡️ CVE-2026-8947 — firefox
Description
Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
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.
Weakness class
CVE-2026-8947 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.
Affected software
CVE-2026-8947 is recorded against 2 packages.
- firefox (from 140.0 up to 140.11.0)
- thunderbird (fixed in 140.11)
Timeline and source
Published on 19 May 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.
References
bugzilla.mozilla.org
www.mozilla.org
www.mozilla.org
www.mozilla.org
www.mozilla.org
www.mozilla.org
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
CVE-2026-8947 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| firefox | 140.0 | 140.11.0 |
| thunderbird | — | 140.11 |
References
Similar Threats
- Unknown ALSA-2022:8580
- Unknown ALSA-2022:8554
- Unknown ALSA-2022:7070
- Unknown ALSA-2022:7071
- Unknown ALSA-2022:7020
More CVE 2026 advisories
Browse all of CVE 2026 in the advisory index.
Site Security Check
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CVE-2026-8947 is rated CVSS 7.3 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.
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