CVE-2026-53899

Cross-origin cookies could be leaked when opening a PDF link

Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.

CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox For Ios Firefox Mobile

CVE-2026-53900

Cookie injection was possible when opening a PDF link

Firefox for iOS preserved cookies set on the initial PDF request across cross-origin HTTP redirects in TemporaryDocument, allowing a malicious site to inject arbitrary cookies into requests to an unrelated target domain. This vulnerability was fixed in Firefox for iOS 152.0.

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox For Ios Firefox Mobile

CVE-2026-45173

Idira Identity Browser Extension: Unauthorized Application Interaction via Origin Validation Failure

Idira Identity Browser Extension (Chrome, Firefox, and Edge builds) versions prior to 26.8.1 exhibit an origin validation flaw within its internal web-page verification routines. If an authenticated user navigates to a specially crafted webpage, this interaction could potentially allow a remote attacker to trigger unauthorized application interaction or execution parameters within the context of that authenticated browser session. CyberArk Security Bulletin: CA26-21

CVSS 4.0 · 8.4 High EPSS < 1% KEV · Not listed

Vendors

Cyberark Cyberark Software A Palo Alto Networks Company Google and 3 more

Products

Identity Browser Extensions Identity Browser Extensions Chrome and 3 more

CVE-2026-11799

UXSS in Focus for iOS / Klar Webkit navigation

UXSS in Focus for iOS / Klar Webkit navigation. This vulnerability was fixed in Focus for iOS 151.3.1 and Klar for iOS 151.3.1.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Focus Focus For Ios Klar and 1 more

CVE-2026-8389

JIT miscompilation in the JavaScript Engine: JIT component

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3.

CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox

CVE-2026-10702

JIT miscompilation in the JavaScript Engine: JIT component

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 151.0.3.

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox

CVE-2026-10701

Incorrect boundary conditions in the Graphics: Text component

Incorrect boundary conditions in the Graphics: Text component. This vulnerability was fixed in Firefox 151.0.3.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox

CVE-2026-9308

Arbitrary JavaScript execution in Reader View due to wrong HTML replacement order

Firefox for iOS Reader View replaced page content in its HTML template before replacing other internal placeholders. A malicious page could include a placeholder string that was later substituted with JSON-LD data, potentially resulting in arbitrary JavaScript execution. This vulnerability was fixed in Firefox for iOS 151.2.

CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Firefox For Ios

CVE-2026-9309

Arbitrary JavaScript execution in internal pages via Reader View JSON-LD injection

Firefox for iOS Reader View did not properly escape HTML tags in JSON-LD metadata. A malicious page could inject markup that changed Reader View behavior and leaked sensitive URL parameters. These parameters could then be used to access internal pages, potentially resulting in arbitrary JavaScript execution in an internal origin. This vulnerability was fixed in Firefox for iOS 151.2.

CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Firefox For Ios

CVE-2026-9078

Firefox iOS RTL Domain Rendering Issue in Link Preview

Firefox for iOS displayed specially crafted right-to-left (RTL) and internationalized domain names (IDNs) incorrectly in link preview UI surfaces. A crafted RTL hostname could visually reorder portions of the displayed domain, causing attacker-controlled sites to appear as trusted origins. This vulnerability was fixed in Firefox for iOS 151.1.

CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Firefox For Ios

CVE-2019-7317

libpng: use-after-free in png_image_free in png.c

png_image_free in png.c in libpng 1.6.x before 1.6.37 has a use-after-free because png_image_free_function is called under png_safe_execute.

CVSS 3.1 · 5.3 Medium EPSS 9.4% KEV · Not listed

Vendors

Canonical Debian Hp and 8 more

Products

Ubuntu Linux Debian Linux Xp7 Command View and 32 more

CVE-2026-6785

Memory safety bugs fixed in Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150

Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Thunderbird

CVE-2015-4000

LOGJAM: TLS connections which support export grade DHE key-exchange are vulnerable to MITM attacks

The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.

CVSS 3.1 · 3.7 Low EPSS 99.9% KEV · Not listed

Vendors

Apple Canonical Debian and 10 more

Products

Iphone Os Mac Os X Safari and 28 more

CVE-2026-6783

Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component

Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Thunderbird

CVE-2026-6753

Incorrect boundary conditions in the WebRTC component

Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS 3.1 · 7.3 High EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Thunderbird

CVE-2026-6765

Information disclosure in the Form Autofill component

Information disclosure in the Form Autofill component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Thunderbird

CVE-2026-6778

Invalid pointer in the Audio/Video: Playback component

Invalid pointer in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Thunderbird

CVE-2009-3555

TLS: MITM attacks via session renegotiation

The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft Internet Information Services (IIS) 7.0, mod_ssl in the Apache HTTP Server 2.2.14 and earlier, OpenSSL before 0.9.8l, GnuTLS 2.8.5 and earlier, Mozilla Network Security Services (NSS) 3.12.4 and earlier, multiple Cisco products, and other products, does not properly associate renegotiation handshakes with an existing connection, which allows man-in-the-middle attackers to insert data into HTTPS sessions, and possibly other types of sessions protected by TLS or SSL, by sending an unauthenticated request that is processed retroactively by a server in a post-renegotiation context, related to a "plaintext injection" attack, aka the "Project Mogul" issue.

CVSS 3.1 · 9.8 Critical EPSS 87.3% KEV · Not listed

Vendors

Apache Canonical Debian and 6 more

Products

Http Server Ubuntu Linux Debian Linux and 12 more

CVE-2026-5731

Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2

Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.

CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed

Vendors

Mozilla

Products

Firefox Firefox Esr Thunderbird

CVE-2013-2566

SSL/TLS: Attack against RC4 stream cipher

The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for remote attackers to conduct plaintext-recovery attacks via statistical analysis of ciphertext in a large number of sessions that use the same plaintext.

CVSS 3.1 · 5.9 Medium EPSS 84.4% KEV · Not listed

Vendors

Canonical Fujitsu Mozilla and 1 more

Products

Ubuntu Linux M10-1 M10-1 Firmware and 21 more