CVE-2023-42448

Hydra's contestation period in head datum can be modified during Close transaction, allowing malicious participant to freely modify the contestation deadline

HIGH
8.1
CVSS Score
Published: October 4, 2023 at 06:57 PM UTC
Updated: June 17, 2026 at 06:23 AM UTC
2 products affected across 2 vendorsHydraHydra

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Severity
HIGH8.1
Exploit prediction
EPSS 1.0%
SSVC
No known exploit

Description

Hydra is the layer-two scalability solution for Cardano. Prior to version 0.13.0, the specification states that the contestation period in the datum of the UTxO at the head validator must stay unchanged as the state progresses from Open to Closed (Close transaction), but no such check appears to be performed in the `checkClose` function of the head validator. This would allow a malicious participant to modify the contestation deadline of the head to either allow them to fanout the head without giving another participant the chance to contest, or prevent any participant from ever redistributing the funds locked in the head via a fan-out. Version 0.13.0 contains a patch for this issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.13.0
Affected range stops below 0.13.0, so it looks safe — our inference, not a vendor statement
v < 0.13.0
Affected range stops below 0.13.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20CWE-1284

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