[NEW] [medium] Apache log4j and Log4cxx: Multiple vulnerabilities allow file manipulation

A remote, anonymous attacker can exploit multiple vulnerabilities in Apache log4j and Apache Log4cxx to manipulate files.

CSIRTS triage

What: Multiple vulnerabilities allow a remote, anonymous attacker to manipulate files.
Who is affected: Deployments of Apache log4j and Log4cxx that are vulnerable.
Urgency: Remediation is medium urgency due to the potential for file manipulation by anonymous attackers.
Action: Apply the latest patches for Apache log4j and Log4cxx.

AI-assisted analysis generated from the source advisory — verify against the original.

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EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-498440.81% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 55% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-400230.50% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 41% of all EPSS-scored CVEs.

CVE	CSIRTS overview	External
CVE-2026-49844	coverage & exploitation status	NVD · CVE.org
CVE-2026-40023	coverage & exploitation status	NVD · CVE.org

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.