[NEW] [medium] Composer: Multiple vulnerabilities

mediumCVE-2026-59946 CVE-2026-59947 CVE-2026-59948

A remote, anonymous attacker can exploit multiple vulnerabilities in Composer to bypass security mechanisms, write arbitrary files, or disclose information. Certain configurations may be required for successful exploitation.

CSIRTS triage

vendor: Composer product: Composer Authentication bypass Information disclosure

What: Multiple vulnerabilities allow a remote attacker to bypass security mechanisms, write arbitrary files, or disclose information.
Who is affected: Users of Composer are affected, especially with certain configurations.
Urgency: Remediation is medium urgency due to the nature of the vulnerabilities.
Action: Update to the latest version of Composer.

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

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: medium
Published: 2026-07-09
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2235

Exploitation outlook

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-2026-599460.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.
Low exploitation riskCVE-2026-599470.11% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all scored CVEs.
Low exploitation riskCVE-2026-599480.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-59946	coverage & exploitation status	NVD · CVE.org
CVE-2026-59947	coverage & exploitation status	NVD · CVE.org
CVE-2026-59948	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

Recent advisories for Composer

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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