Vulnerability-Lookup

FKIE_CVE-2026-0809

Vulnerability from fkie_nvd - Published: 2026-03-12 13:16 - Updated: 2026-06-17 10:11

Severity

6.3 (Medium) - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Summary

Use of a custom token encoding algorithm in Streamsoft Prestiż software allows the value of the KSeF (Krajowy System e-Faktur) token to be guessed after analyzing how tokens with know values are encoded. This issue was fixed in version 20.0.380.92.

References

	URL	Tags
	cvd@cert.pl	https://cert.pl/posts/2026/03/CVE-2026-0809
	cvd@cert.pl	https://www.streamsoft.pl/streamsoft-prestiz/

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Streamsoft Presti\u017c",
          "vendor": "Streamsoft",
          "versions": [
            {
              "lessThan": "20.0.380.92",
              "status": "affected",
              "version": "12.2.363.17",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "cvd@cert.pl"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Use of a custom token encoding algorithm in Streamsoft Presti\u017c software allows\u00a0the value of the KSeF (Krajowy System e-Faktur)\u00a0token to be guessed\u00a0after analyzing how tokens with know values are encoded.\n\nThis issue was fixed in version 20.0.380.92."
    },
    {
      "lang": "es",
      "value": "El uso de un algoritmo de codificaci\u00f3n de tokens personalizado en el software Streamsoft Presti? permite adivinar el valor del token KSeF (Krajowy System e-Faktur) despu\u00e9s de analizar c\u00f3mo se codifican los tokens con valores conocidos.\n\nEste problema se solucion\u00f3 en la versi\u00f3n 20.0.380.92."
    }
  ],
  "id": "CVE-2026-0809",
  "lastModified": "2026-06-17T10:11:25.173",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.3,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "cvd@cert.pl",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-0809",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-03-12T14:04:19.633953Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-03-12T13:16:00.723",
  "references": [
    {
      "source": "cvd@cert.pl",
      "url": "https://cert.pl/posts/2026/03/CVE-2026-0809"
    },
    {
      "source": "cvd@cert.pl",
      "url": "https://www.streamsoft.pl/streamsoft-prestiz/"
    }
  ],
  "sourceIdentifier": "cvd@cert.pl",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-261"
        }
      ],
      "source": "cvd@cert.pl",
      "type": "Secondary"
    }
  ]
}

CVE-2026-0809 (GCVE-0-2026-0809)

Vulnerability from cvelistv5 – Published: 2026-03-12 13:02 – Updated: 2026-03-12 14:04

Title

Weak KSeF token encoding in Streamsoft Prestiż

Summary

Severity

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-12 14:04 UTC

CWE

CWE-261 - Weak Encoding for Password

Assigner

CERT-PL ENISA root

References

2 references

URL	Tags
https://www.streamsoft.pl/streamsoft-prestiz/	product
https://cert.pl/posts/2026/03/CVE-2026-0809	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
Streamsoft	Streamsoft Prestiż	Affected: 12.2.363.17 , < 20.0.380.92 (custom)

Credits

Kamil Dąbkowski

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-0809",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-12T14:04:19.633953Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-12T14:04:53.073Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Streamsoft Presti\u017c",
          "vendor": "Streamsoft",
          "versions": [
            {
              "lessThan": "20.0.380.92",
              "status": "affected",
              "version": "12.2.363.17",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Kamil D\u0105bkowski"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Use of a custom token encoding algorithm in Streamsoft Presti\u017c software allows\u0026nbsp;the value of the KSeF (Krajowy System e-Faktur)\u0026nbsp;token to be guessed\u0026nbsp;\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eafter analyzing how tokens with know values are encoded\u003c/span\u003e.\u003cbr\u003e\u003cbr\u003eThis issue was fixed in version 20.0.380.92."
            }
          ],
          "value": "Use of a custom token encoding algorithm in Streamsoft Presti\u017c software allows\u00a0the value of the KSeF (Krajowy System e-Faktur)\u00a0token to be guessed\u00a0after analyzing how tokens with know values are encoded.\n\nThis issue was fixed in version 20.0.380.92."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-261",
              "description": "CWE-261 Weak Encoding for Password",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-12T13:02:24.795Z",
        "orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
        "shortName": "CERT-PL"
      },
      "references": [
        {
          "tags": [
            "product"
          ],
          "url": "https://www.streamsoft.pl/streamsoft-prestiz/"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://cert.pl/posts/2026/03/CVE-2026-0809"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Weak KSeF token encoding in Streamsoft Presti\u017c",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
    "assignerShortName": "CERT-PL",
    "cveId": "CVE-2026-0809",
    "datePublished": "2026-03-12T13:02:24.795Z",
    "dateReserved": "2026-01-09T14:56:38.137Z",
    "dateUpdated": "2026-03-12T14:04:53.073Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.