{
"document": {
"category": "csaf_base",
"csaf_version": "2.0",
"distribution": {
"tlp": {
"label": "WHITE"
}
},
"lang": "en",
"notes": [
{
"category": "legal_disclaimer",
"text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
}
],
"publisher": {
"category": "coordinator",
"contact_details": "cert@ncsc.nl",
"name": "National Cyber Security Centre",
"namespace": "https://www.ncsc.nl/"
},
"title": "CVE-2026-33473",
"tracking": {
"current_release_date": "2026-03-27T20:47:25.392263Z",
"generator": {
"date": "2026-02-17T15:00:00Z",
"engine": {
"name": "V.E.L.M.A",
"version": "1.7"
}
},
"id": "CVE-2026-33473",
"initial_release_date": "2026-03-20T21:41:09.105509Z",
"revision_history": [
{
"date": "2026-03-20T21:41:09.105509Z",
"number": "1",
"summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)."
},
{
"date": "2026-03-20T21:41:14.199499Z",
"number": "2",
"summary": "NCSC Score created."
},
{
"date": "2026-03-24T20:51:36.104119Z",
"number": "3",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
},
{
"date": "2026-03-24T20:51:38.364681Z",
"number": "4",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-24T20:51:58.057363Z",
"number": "5",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (3).| CWES updated (1).| Unknown change."
},
{
"date": "2026-03-24T20:52:01.875577Z",
"number": "6",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-25T18:13:23.192110Z",
"number": "7",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (1)."
},
{
"date": "2026-03-25T18:13:51.805083Z",
"number": "8",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)."
},
{
"date": "2026-03-25T18:13:53.769367Z",
"number": "9",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-25T21:02:15.956051Z",
"number": "10",
"summary": "Description removed for source.| Description created for source.| References created (3)."
},
{
"date": "2026-03-26T00:13:08.878151Z",
"number": "11",
"summary": "Description removed for source.| Description created for source.| Products created (1).| Products removed (1).| References created (3)."
},
{
"date": "2026-03-26T00:50:19.914007Z",
"number": "12",
"summary": "Source connected.| CVE status created. (valid)| EPSS created."
},
{
"date": "2026-03-26T00:50:21.946584Z",
"number": "13",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-27T19:47:11.241184Z",
"number": "14",
"summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)."
},
{
"date": "2026-03-27T19:47:12.928495Z",
"number": "15",
"summary": "NCSC Score updated."
}
],
"status": "interim",
"version": "15"
}
},
"product_tree": {
"branches": [
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/>=0.13",
"product": {
"name": "vers:unknown/>=0.13",
"product_id": "CSAFPID-5911166"
}
}
],
"category": "product_name",
"name": "api"
},
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/>=0.13|<2.2.1",
"product": {
"name": "vers:unknown/>=0.13|<2.2.1",
"product_id": "CSAFPID-5902508"
}
}
],
"category": "product_name",
"name": "vikunja"
}
],
"category": "vendor",
"name": "go-vikunja"
},
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/>=0.13|<2.2.1",
"product": {
"name": "vers:unknown/>=0.13|<2.2.1",
"product_id": "CSAFPID-5944058",
"product_identification_helper": {
"cpe": "cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*"
}
}
}
],
"category": "product_name",
"name": "vikunja"
}
],
"category": "vendor",
"name": "vikunja"
}
]
},
"vulnerabilities": [
{
"cve": "CVE-2026-33473",
"notes": [
{
"category": "description",
"text": "Vikunja is an open-source self-hosted task management platform. Starting in version 0.13 and prior to version 2.2.1, any user that has enabled 2FA can have their TOTP reused during the standard 30 second validity window. Version 2.2.1 patches the issue.",
"title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33473"
},
{
"category": "description",
"text": "Vikunja is an open-source self-hosted task management platform. Starting in version 0.13 and prior to version 2.2.1, any user that has enabled 2FA can have their TOTP reused during the standard 30 second validity window. Version 2.2.1 patches the issue.",
"title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33473.json"
},
{
"category": "description",
"text": "Vikunja has TOTP Reuse During Validity Window in code.vikunja.io/api.\n\nNOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.\n\n(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)\n\nThe additional affected modules and versions are: .",
"title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGO-2026-4805.json?alt=media"
},
{
"category": "description",
"text": "### Summary\nAny user that has enabled 2FA can have their TOTP reused during the standard 30 second validity window.\n\n### Details\nThe below code is called when a user that has 2FA is authenticating to the application. Once they submit a valid username-password-totp combination, the user gets authenticated. If that same TOTP is used for the same user's account again within the validity window, it will allow the other session to authenticate successfully.\n\n**Source**: pkg/user/totp.go:128\n```go\n// ValidateTOTPPasscode validated totp codes of users.\nfunc ValidateTOTPPasscode(s *xorm.Session, passcode *TOTPPasscode) (t *TOTP, err error) {\n\tt, err = GetTOTPForUser(s, passcode.User)\n\tif err != nil {\n\t\treturn\n\t}\n\n\tif !totp.Validate(passcode.Passcode, t.Secret) {\n\t\treturn nil, ErrInvalidTOTPPasscode{Passcode: passcode.Passcode}\n\t}\n\n\treturn\n}\n```\n\nSection 6.5.1 within the [Authentication](https://github.com/OWASP/ASVS/blob/master/5.0/en/0x15-V6-Authentication.md) section of the OWASP ASVS recommends multiple checks, some of which involving TOTPs:\n\n> Verify that lookup secrets, out-of-band authentication requests or codes, and time-based one-time passwords (TOTPs) are only successfully usable once.\n\nThe OWASP WSTG also references this as one of their [checks](https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/04-Authentication_Testing/11-Testing_Multi-Factor_Authentication) to look for:\n\n> Can the OTPs be used more than once?\n\n### PoC\n\nhttps://github.com/user-attachments/assets/19d3b4c3-c219-4f59-b57d-45c9f6a264c8\n\n### Impact\nAny user who uses 2FA could be impacted if their traffic is able to be captured, they're phished/social engineered, or other methods of attack. This disrupts one layer of the defense-in-depth model surrounding 2FA.\n\n### Similar CVEs\n\n- [CVE-2025-6014](https://nvd.nist.gov/vuln/detail/CVE-2025-6014)\n- [CVE-2025-55003](https://nvd.nist.gov/vuln/detail/CVE-2025-55003)\n\n### Remediation\n\nStore a deny-list of TOTP codes for their validity windows and check submitted codes against it to ensure none are being reused. After their validity window has closed, the 2FA code can be removed from the list.",
"title": "github - https://api.github.com/advisories/GHSA-p747-qc5p-773r"
},
{
"category": "description",
"text": "### Summary\nAny user that has enabled 2FA can have their TOTP reused during the standard 30 second validity window.\n\n### Details\nThe below code is called when a user that has 2FA is authenticating to the application. Once they submit a valid username-password-totp combination, the user gets authenticated. If that same TOTP is used for the same user's account again within the validity window, it will allow the other session to authenticate successfully.\n\n**Source**: pkg/user/totp.go:128\n```go\n// ValidateTOTPPasscode validated totp codes of users.\nfunc ValidateTOTPPasscode(s *xorm.Session, passcode *TOTPPasscode) (t *TOTP, err error) {\n\tt, err = GetTOTPForUser(s, passcode.User)\n\tif err != nil {\n\t\treturn\n\t}\n\n\tif !totp.Validate(passcode.Passcode, t.Secret) {\n\t\treturn nil, ErrInvalidTOTPPasscode{Passcode: passcode.Passcode}\n\t}\n\n\treturn\n}\n```\n\nSection 6.5.1 within the [Authentication](https://github.com/OWASP/ASVS/blob/master/5.0/en/0x15-V6-Authentication.md) section of the OWASP ASVS recommends multiple checks, some of which involving TOTPs:\n\n> Verify that lookup secrets, out-of-band authentication requests or codes, and time-based one-time passwords (TOTPs) are only successfully usable once.\n\nThe OWASP WSTG also references this as one of their [checks](https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/04-Authentication_Testing/11-Testing_Multi-Factor_Authentication) to look for:\n\n> Can the OTPs be used more than once?\n\n### PoC\n\nhttps://github.com/user-attachments/assets/19d3b4c3-c219-4f59-b57d-45c9f6a264c8\n\n### Impact\nAny user who uses 2FA could be impacted if their traffic is able to be captured, they're phished/social engineered, or other methods of attack. This disrupts one layer of the defense-in-depth model surrounding 2FA.\n\n### Similar CVEs\n\n- [CVE-2025-6014](https://nvd.nist.gov/vuln/detail/CVE-2025-6014)\n- [CVE-2025-55003](https://nvd.nist.gov/vuln/detail/CVE-2025-55003)\n\n### Remediation\n\nStore a deny-list of TOTP codes for their validity windows and check submitted codes against it to ensure none are being reused. After their validity window has closed, the 2FA code can be removed from the list.",
"title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGHSA-p747-qc5p-773r.json?alt=media"
},
{
"category": "other",
"text": "0.00027",
"title": "EPSS"
},
{
"category": "other",
"text": "3.5",
"title": "NCSC Score"
},
{
"category": "other",
"text": "Exploit code publicly available, There is exploit data available from source Nvd, The value of the most recent EPSS score, Is related to (a version of) an uncommon product",
"title": "NCSC Score top decreasing factors"
}
],
"product_status": {
"known_affected": [
"CSAFPID-5902508",
"CSAFPID-5911166",
"CSAFPID-5944058"
]
},
"references": [
{
"category": "external",
"summary": "Source - github",
"url": "https://api.github.com/advisories/GHSA-p747-qc5p-773r"
},
{
"category": "external",
"summary": "Source - nvd",
"url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33473"
},
{
"category": "external",
"summary": "Source - cveprojectv5",
"url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33473.json"
},
{
"category": "external",
"summary": "Source - osv",
"url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGO-2026-4805.json?alt=media"
},
{
"category": "external",
"summary": "Source - osv",
"url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGHSA-p747-qc5p-773r.json?alt=media"
},
{
"category": "external",
"summary": "Source - first",
"url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd; osv",
"url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-p747-qc5p-773r"
},
{
"category": "external",
"summary": "Reference - github",
"url": "https://github.com/advisories/GHSA-p747-qc5p-773r"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd; osv",
"url": "https://vikunja.io/changelog/vikunja-v2.2.0-was-released"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd; osv",
"url": "https://vikunja.io/changelog/vikunja-v2.2.2-was-released"
},
{
"category": "external",
"summary": "Reference - github; osv",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33473"
}
],
"scores": [
{
"cvss_v3": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N",
"baseScore": 5.7,
"baseSeverity": "MEDIUM"
},
"products": [
"CSAFPID-5902508",
"CSAFPID-5911166",
"CSAFPID-5944058"
]
}
],
"title": "CVE-2026-33473"
}
]
}