Cyber Resilience

CVE-2026-7322

Memory Safety in Mozilla Firefox ≤ 115.35.1

Published
28 April 2026
Modified
15 July 2026
Patch / advisory
CVSS Score v3.1 7.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0032 24th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-7322 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Mozilla Firefox. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-7322 encompasses multiple memory safety bugs, classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-416 (Use After Free), affecting Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. These bugs demonstrate evidence of memory corruption, which Mozilla assesses as potentially exploitable for arbitrary code execution with sufficient effort. The vulnerability carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L) and was published on 2026-04-28.

Remote attackers can exploit this vulnerability over the network with low complexity, without requiring user privileges or interaction. Successful exploitation could enable arbitrary code execution through memory corruption, resulting in low impacts to confidentiality, integrity, and availability within the affected Thunderbird processes.

Mozilla advisories MFSA2026-35 through MFSA2026-38 detail the fixes, available in Firefox 150.0.1, Firefox ESR 140.10.1, Firefox ESR 115.35.1, Thunderbird 150.0.1, and Thunderbird ESR 140.10.1. Additional technical details are provided in the associated Bugzilla entries. Security practitioners should prioritize updating affected Thunderbird installations to mitigate this issue.

EU & UK References

Vulnerability Data

Memory safety bugs present in Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. 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…

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was fixed in Firefox 150.0.1, Firefox ESR 140.10.1, Firefox ESR 115.35.1, Thunderbird 150.0.1, and Thunderbird 140.10.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-16367Same product: Mozilla Firefox
CVE-2026-12314Same product: Mozilla Firefox
CVE-2026-12310Same product: Mozilla Firefox
CVE-2026-12292Same product: Mozilla Firefox
CVE-2025-14333Same product: Mozilla Firefox
CVE-2026-7323Same product: Mozilla Firefox
CVE-2026-8973Same product: Mozilla Firefox
CVE-2026-8946Same product: Mozilla Firefox
CVE-2026-5731Same product: Mozilla Firefox
CVE-2026-6753Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 115.35.1 · ≤ 150.0.1 · 128.0 — 140.10.1
mozilla
thunderbird
≤ 140.10.1 · ≤ 150.0.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V17.3.2
  • V1.4.3

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover use-after-free bugs through dynamic analysis or fuzzing.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.

Process isolation confines the blast radius of use-after-free memory corruption to a single execution domain.

Input validation directly enforces bounds checking that stops out-of-bounds reads/writes from being introduced or reached.

Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

prevents

Change-management processes help ensure memory-safety fixes are deployed consistently.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248592 OL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416
RHEL 8 (1 rule)
  • V-230279 RHEL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416
RHEL 9 (1 rule)
  • V-257794 RHEL 9 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416

References