{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-75870",
        "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "state": "PUBLISHED",
        "assignerShortName": "CPANSec",
        "dateReserved": "2026-08-18T11:59:49.642Z",
        "datePublished": "2026-08-22T13:35:58.346Z",
        "dateUpdated": "2026-08-25T19:28:36.443Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "collectionURL": "https://cpan.org/modules",
                    "defaultStatus": "unaffected",
                    "modules": [
                        "Punk"
                    ],
                    "packageName": "Punk",
                    "packageURL": "pkg:cpan/Punk",
                    "programFiles": [
                        "xs/app.xs",
                        "include/punk/punk_session.h"
                    ],
                    "programRoutines": [
                        {
                            "name": "Punk::App::session"
                        },
                        {
                            "name": "ps_load"
                        },
                        {
                            "name": "ps_writeback"
                        }
                    ],
                    "versions": [
                        {
                            "lessThan": "0.18",
                            "status": "affected",
                            "version": "0",
                            "versionType": "custom"
                        }
                    ]
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Punk versions before 0.18 for Perl allow session cookie forgery via an empty default HMAC key when a session is declared without a secret.\n\nThe session keyword freezes its options onto the application as given: it does not require a secret, warn, or refuse to start when one is absent. The cookie read and the write-back both default that key to the empty string, so a declaration with no secret option, or with an undefined or empty one, signs and verifies with a zero-length HMAC-SHA256 key.\n\nAn attacker who knows the cookie format can then mint one offline carrying any contents the session holds, such as a user identifier or a role. Nothing marks the misconfiguration at runtime: cookies are well formed and sessions round-trip as expected."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1394",
                            "description": "CWE-1394 Use of Default Cryptographic Key",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
                "shortName": "CPANSec",
                "dateUpdated": "2026-08-22T13:35:58.346Z"
            },
            "references": [
                {
                    "tags": [
                        "technical-description"
                    ],
                    "url": "https://metacpan.org/release/LNATION/Punk-0.17/source/include/punk/punk_session.h"
                },
                {
                    "tags": [
                        "technical-description"
                    ],
                    "url": "https://metacpan.org/release/LNATION/Punk-0.17/view/lib/Punk.pm"
                },
                {
                    "tags": [
                        "release-notes"
                    ],
                    "url": "https://metacpan.org/release/LNATION/Punk-0.18/source/Changes"
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "Upgrade to Punk 0.18 or later."
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "Punk versions before 0.18 for Perl allow session cookie forgery via an empty default HMAC key when a session is declared without a secret",
            "workarounds": [
                {
                    "lang": "en",
                    "value": "For deployments that cannot upgrade to 0.18, declare the session keyword with a non-empty secret. The secret keyword fails closed, so sourcing the key through it turns a missing configuration path or an unset environment variable into a startup error."
                }
            ],
            "x_generator": {
                "engine": "cpansec-cna-tool 0.1"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "http://www.openwall.com/lists/oss-security/2026/08/22/5"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2026-08-22T19:07:10.053Z"
                }
            },
            {
                "metrics": [
                    {
                        "cvssV3_1": {
                            "scope": "UNCHANGED",
                            "version": "3.1",
                            "baseScore": 9.1,
                            "attackVector": "NETWORK",
                            "baseSeverity": "CRITICAL",
                            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
                            "integrityImpact": "HIGH",
                            "userInteraction": "NONE",
                            "attackComplexity": "LOW",
                            "availabilityImpact": "NONE",
                            "privilegesRequired": "NONE",
                            "confidentialityImpact": "HIGH"
                        }
                    },
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-25T19:27:34.454527Z",
                                "id": "CVE-2026-75870",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-25T19:28:36.443Z"
                }
            }
        ]
    }
}