How severe is CVE-2026-2806?

CVE-2026-2806 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2026-2806 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-2806?

CVE-2026-2806 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-2806?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-2806 have an EU (EUVD) identifier?

Yes. CVE-2026-2806 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8459.

When was CVE-2026-2806 published?

CVE-2026-2806 was published on 2026-02-24 and last updated on 2026-06-17.

CVE-2026-2806

CVE-2026-2806 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-908.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8459
Weakness: CWE-908
Affected product: Mozilla Firefox
Published: 2026-02-24
Last modified: 2026-06-17

Description

Uninitialized memory in the Graphics: Text component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

Frequently asked questions

What is CVE-2026-2806?: Uninitialized memory in the Graphics: Text component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.
How severe is CVE-2026-2806?: CVE-2026-2806 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-2806 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-2806?: CVE-2026-2806 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-2806?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-2806 have an EU (EUVD) identifier?: Yes. CVE-2026-2806 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8459.
When was CVE-2026-2806 published?: CVE-2026-2806 was published on 2026-02-24 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

More vulnerabilities in Mozilla Firefox

CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…

All CVEs affecting Mozilla Firefox →

Other CWE-908 (Use of Uninitialized Resource) vulnerabilities

CVE-2025-1942 — Critical (CVSS 9.8): When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated…
CVE-2024-47540 — Critical (CVSS 9.8): GStreamer is a library for constructing graphs of media-handling components. An uninitialized stack variable…
CVE-2024-32611 — Critical (CVSS 9.8): HDF5 Library through 1.14.3 may use an uninitialized value in H5A__attr_release_table in H5Aint.c.
CVE-2023-24941 — Critical (CVSS 9.8): Windows Network File System Remote Code Execution Vulnerability
CVE-2022-26437 — Critical (CVSS 9.8): In httpclient, there is a possible out of bounds write due to uninitialized data. This could lead to remote escalation…
CVE-2021-45703 — Critical (CVSS 9.8): An issue was discovered in the tectonic_xdv crate before 0.1.12 for Rust. XdvParser::<T>::process may read from…

Browse all CWE-908 (Use of Uninitialized Resource) vulnerabilities →