CVE-2023-29019
Session fixation in fastify-passport
@fastify/passport is a port of passport authentication library for the Fastify ecosystem. Applications using @fastify/passport in affected versions for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers. fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website. As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.1
Session fixation in fastify-passport
@fastify/passport is a port of passport authentication library for the Fastify ecosystem. Applications using @fastify/passport in affected versions for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers. fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website. As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Record
CVE-2023-29019- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-384
- Updated
- 2026-11-02
EUVDEUVD-2023-1192
8.1
@fastify/passport is a port of passport authentication library for the Fastify ecosystem. Applications using @fastify/passport in affected versions for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers. fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website. As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Record
EUVD-2023-1192- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4m3m-ppvx-xgw9
8.1
Session fixation in fastify-passport
Applications using @fastify/passport for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers.
Details
fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website.
Fix
As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session.
Credits
- Pedro Adão (@pedromigueladao), Instituto Superior Técnico, University of Lisbon
- Marco Squarcina (@lavish), Security & Privacy Research Unit, TU Wien
- Record
GHSA-4m3m-ppvx-xgw9- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-384
- Updated
- 2026-11-02
NVD
8.1
@fastify/passport is a port of passport authentication library for the Fastify ecosystem. Applications using @fastify/passport in affected versions for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers. fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website. As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Record
CVE-2023-29019- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-384
- Updated
- 2026-11-02
OSV
8.1
Session fixation in fastify-passport
@fastify/passport is a port of passport authentication library for the Fastify ecosystem. Applications using @fastify/passport in affected versions for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers. fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website. As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session. Users are advised to upgrade. There are no known workarounds for this vulnerability.
- Record
CVE-2023-29019- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-384
- Updated
- 2026-11-02
OSVGHSA-4m3m-ppvx-xgw9
8.1
Session fixation in fastify-passport
Applications using @fastify/passport for user authentication, in combination with @fastify/session as the underlying session management mechanism, are vulnerable to session fixation attacks from network and same-site attackers.
Details
fastify applications rely on the @fastify/passport library for user authentication. The login and user validation are performed by the authenticate function. When executing this function, the sessionId is preserved between the pre-login and the authenticated session. Network and same-site attackers can hijack the victim's session by tossing a valid sessionId cookie in the victim's browser and waiting for the victim to log in on the website.
Fix
As a solution, newer versions of @fastify/passport regenerate sessionId upon login, preventing the attacker-controlled pre-session cookie from being upgraded to an authenticated session.
Credits
- Pedro Adão (@pedromigueladao), Instituto Superior Técnico, University of Lisbon
- Marco Squarcina (@lavish), Security & Privacy Research Unit, TU Wien
- Record
GHSA-4m3m-ppvx-xgw9- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-384
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@fastify/passportnpm |
before 1.1.0 | 1.1.0 |
@fastify/passportnpm |
2.0.0 up to 2.3.0 | 2.3.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-29019 is a high vulnerability (CVSS 8.1) in Fastify Fastify-passport, published April 21, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.75%, the 55th percentile. Fixed in @fastify/passport 1.1.0.
References
github.com/fastify/fastify-passport/security/advisories/GHSA-4m3m-ppvx-xgw9
github.com/fastify/fastify-passport/commit/43c82c321db58ea3e375dd475de60befbfcf2a11
owasp.org/www-community/attacks/Session_fixation
nvd.nist.gov/vuln/detail/CVE-2023-29019
github.com/advisories/GHSA-4m3m-ppvx-xgw9
github.com/CVEProject/cvelistV5/tree/main/cves/2023/29xxx/CVE-2023-29019.json
github.com/fastify/fastify-passport