This vulnerability is a use‑after‑free error in the Networking component of Mozilla Firefox. A handle to a freed object can be accessed after the memory has been repurposed, allowing an attacker to corrupt data or execute arbitrary code. The impact is potentially complete compromise of the process owning the memory, leading to loss of confidentiality, integrity, and availability of the affected system. The admission that this was fixed in future releases signals the severity of the flaw.

Mozilla Firefox is affected, with the problem prevalent in any version before 159 and in the ESR releases before 115.44 and 153.6. Users of those builds must upgrade to the patched releases to avoid exploitation.

No EPSS score is available and the vulnerability is not listed in CISA KEV, implying no documented exploitation yet. However, use‑after‑free weaknesses are classically exploitable via crafted network traffic or malicious content, and the absence of mitigation in the affected binaries means an attacker could potentially trigger it reasonably easily. The CVSS score is not disclosed, but the nature of the flaw warrants a high severity assessment. Stakeholders should consider the risk significant until the fixes are applied.