SB2026022568 - Debian update for firefox-esr
Published: February 25, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 36 secuirty vulnerabilities.
1) Buffer overflow (CVE-ID: CVE-2026-2757)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content in WebRTC: Audio/Video component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
2) Use-after-free (CVE-ID: CVE-2026-2758)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in JavaScript: GC component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
3) Buffer overflow (CVE-ID: CVE-2026-2759)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content in the Graphics: ImageLib component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
4) Buffer overflow (CVE-ID: CVE-2026-2760)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content in in the Graphics: WebRender component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption to bypass sandbox restrictions and execute arbitrary code on the target system.
5) Buffer overflow (CVE-ID: CVE-2026-2761)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content in in the Graphics: WebRender component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption to bypass sandbox restrictions and execute arbitrary code on the target system.
6) Integer overflow (CVE-ID: CVE-2026-2762)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow in the JavaScript: Standard Library component. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
7) Use-after-free (CVE-ID: CVE-2026-2763)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
8) Use-after-free (CVE-ID: CVE-2026-2764)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the JavaScript Engine: JIT component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
9) Use-after-free (CVE-ID: CVE-2026-2765)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.
10) Use-after-free (CVE-ID: CVE-2026-2766)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the JavaScript Engine: JIT component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.
11) Use-after-free (CVE-ID: CVE-2026-2767)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the JavaScript: WebAssembly component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.
12) Protection mechanism failure (CVE-ID: CVE-2026-2768)
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to insufficient implementation of security measures in the Storage: IndexedDB component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.
13) Use-after-free (CVE-ID: CVE-2026-2769)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the Storage: IndexedDB component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
14) Use-after-free (CVE-ID: CVE-2026-2770)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the DOM: Bindings (WebIDL) component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
15) Improper Neutralization of Special Elements in Output Used by a Downstream Component (CVE-ID: CVE-2026-2771)
The vulnerability allows a remote attacker to execute arbitrary code on the system.
The vulnerability exists due to improper input validation in the DOM: Core & HTML component. A remote attacker can execute arbitrary JavaScript code in the browser leading to a system compromise.
16) Use-after-free (CVE-ID: CVE-2026-2772)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in the Audio/Video: Playback component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.
17) Buffer overflow (CVE-ID: CVE-2026-2773)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in the Web Audio component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
18) Integer overflow (CVE-ID: CVE-2026-2774)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow in the Audio/Video component. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and execute arbitrary code on the target system.
19) Protection mechanism failure (CVE-ID: CVE-2026-2775)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to insufficient implementation of security measures in the DOM: HTML Parser component. An attacker can trick the victim into visiting a specially crafted website and compromise the affected system.
20) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2026-2777)
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to application does not properly impose security restrictions in the Messaging System component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.
21) Buffer overflow (CVE-ID: CVE-2026-2778)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML code in the DOM: Core & HTML component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
22) Buffer overflow (CVE-ID: CVE-2026-2779)
The vulnerability allows a remote attacker to crash the browser.
The vulnerability exists due to a boundary error when processing HTML content in the Networking: JAR component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and crash the browser.
23) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2026-2780)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to application does not properly impose security restrictions in the Netmonitor component. A remote attacker can escalate privileges on the system.
24) Integer overflow (CVE-ID: CVE-2026-2781)
The vulnerability allows a remote attacker to crash the browser.
The vulnerability exists due to integer overflow in the Libraries component in NSS. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and crash the browser.
25) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2026-2782)
The vulnerability allows a remote attacker to escalate privileges on the system.
The vulnerability exists due to application does not properly impose security restrictions in the Netmonitor component. A remote attacker can escalate privileges on the system.
26) Information disclosure (CVE-ID: CVE-2026-2783)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to JIT miscompilation in the JavaScript Engine: JIT component. A remote attacker can gain unauthorized access to sensitive information.
27) Protection mechanism failure (CVE-ID: CVE-2026-2784)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to insufficient implementation of security measures in the DOM: Security component. An attacker can bypass implemented security restrictions.
28) NULL pointer dereference (CVE-ID: CVE-2026-2785)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser.
29) Use-after-free (CVE-ID: CVE-2026-2786)
The vulnerability allows a remote attacker to crash the browser.
The vulnerability exists due to a use-after-free error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser.
30) Use-after-free (CVE-ID: CVE-2026-2787)
The vulnerability allows a remote attacker to crash the browser.
The vulnerability exists due to a use-after-free error in the DOM: Window and Location component. A remote attacker can trick the victim into visiting a specially crafted webpage and crash the browser.
31) Buffer overflow (CVE-ID: CVE-2026-2788)
The vulnerability allows a remote attacker to crash the browser
The vulnerability exists due to a boundary error in the Audio/Video: GMP component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser.
32) Use-after-free (CVE-ID: CVE-2026-2789)
The vulnerability allows a remote attacker to crash the browser.
The vulnerability exists due to a use-after-free error in the Graphics: ImageLib component. A remote attacker can trick the victim into visiting a specially crafted webpage and crash the browser.
33) Protection mechanism failure (CVE-ID: CVE-2026-2790)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to insufficient implementation of security measures in the Networking: JAR component. An attacker can bypass same-origin policy.
34) Protection mechanism failure (CVE-ID: CVE-2026-2791)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to insufficient implementation of security measures in the Networking: Cache component. An attacker can bypass implemented security restrictions.
35) Buffer overflow (CVE-ID: CVE-2026-2792)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
36) Buffer overflow (CVE-ID: CVE-2026-2793)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
Remediation
Install update from vendor's website.