CVE-2020-5300Disallow replay of `private_key_jwt` by blacklisting JTIs in Hydra
- 5.8MediumCVSS base score
- 1.0%Exploitation in 30 daysEPSS · top 36% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In Hydra (an OAuth2 Server and OpenID Certified™ OpenID Connect Provider written in Go), before version 1.4.0+oryOS.17, when using client authentication method 'private_key_jwt' [1], OpenId specification says the following about assertion `jti`: "A unique identifier for the token, which can be used to prevent reuse of the token. These tokens MUST only be used once, unless conditions for reuse were negotiated between the parties". Hydra does not check the uniqueness of this `jti` value. Exploiting this vulnerability is somewhat difficult because: - TLS protects against MITM which makes it difficult to intercept valid tokens for replay attacks - The expiry time of the JWT gives only a short window of opportunity where it could be replayed This has been patched in version v1.4.0+oryOS.17
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium5.8 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 1.0% · top 36% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.8.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/ory/hydraGHSA-3p3g-vpw6-4w66 (opens in a new tab)
References
References3
- https://github.com/ory/hydra/security/advisories/GHSA-3p3g-vpw6-4w66 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/ory/hydra/commit/700d17d3b7d507de1b1d459a7261d6fb2571ebe3 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/ory/hydra/releases/tag/v1.4.0 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-0921 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-3p3g-vpw6-4w66 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-5300)Record last updated .