CVE-2026-100783
published 2026-09-29CVE-2026-100783: Uninitialized memory in the Audio/Video component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4…
PriorityP420medium4.3CVSS 3.1
AVNACLPRNUIRSUCNINAL
EPSS
0.28%
19.1th percentile
Uninitialized memory in the Audio/Video component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 157 | Firefox 157 |
| mozilla | firefox | < 115.42.0 | 115.42.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 116.0 < 140.17.0 | 140.17.0 |
| mozilla | firefox | >= 141.0 < 153.4.0 | 153.4.0 |
| mozilla | firefox | >= 154.0.0 < 157.0.0 | 157.0.0 |
| mozilla | firefox_esr | < Firefox ESR 140.17 | Firefox ESR 140.17 |
| mozilla | firefox_esr | < Firefox ESR 115.42 | Firefox ESR 115.42 |
| mozilla | firefox_esr | < Firefox ESR 153.4 | Firefox ESR 153.4 |
| mozilla | thunderbird | < Thunderbird 140.17 | Thunderbird 140.17 |
| mozilla | thunderbird | < Thunderbird 157 | Thunderbird 157 |
| mozilla | thunderbird | < Thunderbird 153.4 | Thunderbird 153.4 |
| mozilla | thunderbird | < 140.17.0 | 140.17.0 |
| mozilla | thunderbird | — | — |
| mozilla | thunderbird | >= 141.0 < 153.4.0 | 153.4.0 |
| mozilla | thunderbird | >= 154.0 < 157.0 | 157.0 |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
vendor_redhat4.3MEDIUM
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Red Hat
firefox: thunderbird: Uninitialized memory in the Audio/Video component
vendor_redhat·2026-09-29·CVSS 4.3
CVE-2026-100783 [MEDIUM] CWE-908 firefox: thunderbird: Uninitialized memory in the Audio/Video component
firefox: thunderbird: Uninitialized memory in the Audio/Video component
Uninitialized memory in the Audio/Video component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Uninitialized memory in the Audio/Video component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Mitigation: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread
Mozilla
Mozilla Foundation Security Advisory 2026-99: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-99: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-99
CVE: CVE-2026-100783
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 140.17
Mozilla
Mozilla Foundation Security Advisory 2026-102: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-102: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-102
CVE: CVE-2026-100783
Product: Thunderbird
Impact: moderate
Fixed in: Thunderbird 140.17
Mozilla
Mozilla Foundation Security Advisory 2026-98: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-98: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-98
CVE: CVE-2026-100783
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 115.42
Mozilla
Mozilla Foundation Security Advisory 2026-97: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-97: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-97
CVE: CVE-2026-100783
Product: Firefox
Impact: low
Fixed in: Firefox 157
Mozilla
Mozilla Foundation Security Advisory 2026-100: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-100: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-100
CVE: CVE-2026-100783
Product: Firefox ESR
Impact: low
Fixed in: Firefox ESR 153.4
Mozilla
Mozilla Foundation Security Advisory 2026-101: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-101: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-101
CVE: CVE-2026-100783
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 157
Mozilla
Mozilla Foundation Security Advisory 2026-103: CVE-2026-100783
vendor_mozilla·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Foundation Security Advisory 2026-103: CVE-2026-100783
Mozilla Foundation Security Advisory 2026-103
CVE: CVE-2026-100783
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 153.4
VulDB
Mozilla Firefox up to 115.41/140.16/153.3/156 Audio Video uninitialized pointer (Nessus ID 351383 / WID-SEC-2026-3654)
vuldb·2026-10-03·CVSS 4.3
CVE-2026-100783 [MEDIUM] Mozilla Firefox up to 115.41/140.16/153.3/156 Audio Video uninitialized pointer (Nessus ID 351383 / WID-SEC-2026-3654)
A vulnerability has been found in Mozilla Firefox up to 115.41/140.16/153.3/156 and classified as critical. The affected element is an unknown function of the component Audio Video. Performing a manipulation results in uninitialized pointer.
This vulnerability is identified as CVE-2026-100783. The attack can be initiated remotely. There is not any exploit available.
The affected component should be upgraded.
GHSA
Uninitialized memory in the Audio/Video component.
ghsa_unreviewed·2026-09-29
CVE-2026-100783 [MEDIUM] CWE-457 Uninitialized memory in the Audio/Video component.
Uninitialized memory in the Audio/Video component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2069804https://www.mozilla.org/security/advisories/mfsa2026-100/https://www.mozilla.org/security/advisories/mfsa2026-101/https://www.mozilla.org/security/advisories/mfsa2026-102/https://www.mozilla.org/security/advisories/mfsa2026-103/https://www.mozilla.org/security/advisories/mfsa2026-97/https://www.mozilla.org/security/advisories/mfsa2026-98/https://www.mozilla.org/security/advisories/mfsa2026-99/
2026-09-29
Published