concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption_CVE-2026-54906

{
    "lastseen": "",
    "description": "concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLock#release_write_lock does not verify that the calling thread acquired the write lock. Any thread with access to the lock object can release an active write lock held by another thread. A second writer can then enter its critical section while the first writer is still running. Concurrent::ReadWriteLock#release_read_lock also decrements the shared counter even when no read lock is held. Calling it on a fresh lock changes the counter from 0 to -1, after which normal read acquisition raises Concurrent::ResourceLimitError. This is a synchronization correctness issue in the public Concurrent::ReadWriteLock API. This vulnerability is fixed in 1.3.7.",
    "published": "2026-06-24T15:46:01.116Z",
    "modified": "2026-06-24T15:46:01.116Z",
    "type": "cve",
    "title": "concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption",
    "source": "GitHub_M",
    "references": "https://github.com/ruby-concurrency/concurrent-ruby/security/advisories/GHSA-6wx8-w4f5-wwcr",
    "id": "CVE-2026-54906",
    "bulletinFamily": "",
    "cwe": [
        "CWE-414",
        "CWE-667"
    ],
    "cvelist": null,
    "sourceData": "ruby-concurrency concurrent-ruby < 1.3.7",
    "sourceHref": "",
    "cvss": {
        "score": 2.1,
        "severity": "LOW",
        "vector": "CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "concurrent-ruby",
    "version": "< 1.3.7",
    "vendor": "ruby-concurrency",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}