CVE-2026-2801 [High] | Security Vulnerability in Firefox

CVE-2026-2801 is rated Low Risk (35.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-03-02	0.02%	0.05%	+0.03%
2	2026-02-25	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-03-02

0.02%

0.05%

+0.03%

2026-02-25

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	[email protected]
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

[email protected]

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2026-2801

vendor	priority	summary	link
`alpine`	—	CVE-2026-2801: 2 source package rows (firefox, thunderbird); 179 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 179.	https://security.alpinelinux.org/vuln/CVE-2026-2801
`debian`	not yet assigned	CVE-2026-2801 not yet assigned priority: Debian including 1 source packages (firefox), 1 status rows across 1 suites (sid): resolved 1.	https://security-tracker.debian.org/tracker/CVE-2026-2801
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2026-2801
`suse`	high	—	https://www.suse.com/security/cve/CVE-2026-2801/
`ubuntu`	medium	CVE-2026-2801 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 49 status rows across 7 suites (bionic, focal, jammy, noble, questing, resolute, upstream): DNE 23, needs-triage 10, ignored 8, not-affected 7, needed 1.	https://ubuntu.com/security/CVE-2026-2801

Affected software / configurations for CVE-2026-2801

Vendor	Product	Version	Raw CPE
mozilla	firefox	< 148.0	cpe:2.3:a:mozilla:firefox:::::-:::*
mozilla	thunderbird	< 148.0	cpe:2.3:a:mozilla:thunderbird:::::-:::*

References for CVE-2026-2801

URL	Tags
https://bugzilla.mozilla.org/show_bug.cgi?id=2009901	Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-13/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-16/	Vendor Advisory

URL

CVE-2026-2801 | Incorrect boundary conditions in the JavaScript: WebAssembly component

Exploit prediction scoring system (EPSS) score for CVE-2026-2801

Common vulnerability scoring system (CVSS) metrics for CVE-2026-2801

Weakness enumeration for CVE-2026-2801

OS Trackers for CVE-2026-2801

Affected software / configurations for CVE-2026-2801

References for CVE-2026-2801