CVE-2025-1009

Description

An attacker could have caused a use-after-free via crafted XSLT data, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

CVSS v3.1 Score

9.8

CRITICAL

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

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
mozilla	firefox	< 115.20.0
mozilla	firefox	< 135.0
mozilla	firefox	128.1.0 — 128.7.0
mozilla	thunderbird	128.0.1 — 128.7.0
mozilla	thunderbird	131.0 — 135.0

References

Advisories & Patches

https://www.mozilla.org/security/advisories/mfsa2025-07/ https://www.mozilla.org/security/advisories/mfsa2025-08/ https://www.mozilla.org/security/advisories/mfsa2025-09/ https://www.mozilla.org/security/advisories/mfsa2025-10/ https://www.mozilla.org/security/advisories/mfsa2025-11/

Other References

https://bugzilla.mozilla.org/show_bug.cgi?id=1936613 https://lists.debian.org/debian-lts-announce/2025/02/msg00005.html https://lists.debian.org/debian-lts-announce/2025/02/msg00006.html

Frequently Asked Questions

What is CVE-2025-1009? +

An attacker could have caused a use-after-free via crafted XSLT data, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2025-1009? +

CVE-2025-1009 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

What products are affected by CVE-2025-1009? +

CVE-2025-1009 affects products from mozilla, specifically: firefox, thunderbird. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-1009? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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