CVE-2023-38701
CVSS v3
9.1
CRITICAL
EPSS Score
1.1 %
exploit probability, as of 2026-10-05
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Hydra is the layer-two scalability solution for Cardano. Users of the Hydra head protocol send the UTxOs they wish to commit into the Hydra head first to the `commit` validator, where they remain until they are either collected into the `head` validator or the protocol initialisation is aborted and the value in the committed UTxOs is returned to the users who committed them. Prior to version 0.12.0, the `commit` validator contains a flawed check when the `ViaAbort` redeemer is used, which allows any user to spend any UTxO which is at the validator arbitrarily, meaning an attacker can steal the funds that users are trying to commit into the head validator. The intended behavior is that the funds must be returned to the user which committed the funds and can only be performed by a participant of the head. The `initial` validator also is similarly affected as the same flawed check is performed for the `ViaAbort` redeemer. Due to this issue, an attacker can steal any funds that user's try to commit into a Hydra head. Also, an attacker can prevent any Hydra head from being successfully opened. It does not allow an attacker to take funds which have been successfully collected into and currently reside in the `head` validator. Version 0.12.0 contains a fix for this issue.
Technical details
- Published
- 2023-10-04
Frequently asked questions
What is CVE-2023-38701?
Hydra is the layer-two scalability solution for Cardano. Users of the Hydra head protocol send the UTxOs they wish to commit into the Hydra head first to the `commit` validator, where they remain until they are either collected into the `head` validator or the protocol initialisation is aborted and the value in the committed UTxOs is returned to the users who committed them. Prior to version 0.12.0, the `commit` validator contains a flawed check when the `ViaAbort` redeemer is used, which allows any user to spend any UTxO which is at the validator arbitrarily, meaning an attacker can steal the funds that users are trying to commit into the head validator. The intended behavior is that the funds must be returned to the user which committed the funds and can only be performed by a participant of the head. The `initial` validator also is similarly affected as the same flawed check is performed for the `ViaAbort` redeemer. Due to this issue, an attacker can steal any funds that user's try to commit into a Hydra head. Also, an attacker can prevent any Hydra head from being successfully opened. It does not allow an attacker to take funds which have been successfully collected into and currently reside in the `head` validator. Version 0.12.0 contains a fix for this issue.
Is CVE-2023-38701 actively exploited?
Active exploitation of CVE-2023-38701 has not been confirmed. Its EPSS score was 1.1% on 2026-10-05, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2023-38701?
CVE-2023-38701 has a CVSS v3 base score of 9.1 (CRITICAL severity).
Is CVE-2023-38701 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.
No credit card required · 50 free checks/month · Free API key
Other 2023 vulnerabilities worth triaging
Ranked by exploit probability (EPSS).