High · CVSS 8.2CVE-2026-62162

Hydra: Deposit Claim omits Head state-token spending requirementCVE-2026-62162

Answer in brief

CVE-2026-62162 records a High severity (CVSS 8.2) vulnerability in Hydra: Deposit Claim omits Head state-token spending requirement. The current sources do not mark it as known exploited. The current feed maps cardano-scaling/hydra (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 30, 2026Updated Oct 30, 2026Source checked Oct 30, 2026First seen by HOL Oct 30, 2026Material review Oct 30, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.2
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps cardano-scaling/hydra (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
cardano-scaling/hydrageneric	<2.1.0	2.1.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for cardano-scaling/hydra.
Review the reported fix. Update cardano-scaling/hydra to 2.1.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 30, 2026

Sources and claim methodology

Upstream source description

Hydra is a layer-two scalability solution for Cardano. Prior to 2.1.0, the `Claim` branch in `hydra-plutus/validators/deposit.ak` checks only that `datum.head_id` matches the attacker-controlled `redeemer.currencySymbol` and that the transaction is valid before the deposit deadline. It neither requires spending the Head state-token UTxO in the same transaction nor constrains outputs. After a deposit made through `POST /commit` is confirmed, any third party able to build a Cardano transaction can observe and consume the pending deposit UTxO before its deadline and redirect the assets to an arbitrary address. A standalone deposit spend invokes no Head validator, bypassing its safety checks; historical head-ID binding and the Aiken rewrite retained this missing invariant. The default deadline is three times depositPeriod, so the described attack applies to pending deposits before that deadline. This issue is fixed in version 2.1.0.

Quoted source text, attributed separately from HOL analysis.