fix(deps): update dependency marshmallow to v3.26.2 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
marshmallow (changelog)	3.22.0 → 3.26.2

Review

• Updates have been tested and work
• If updates are AWS related, versions match the infrastructure (e.g. Lambda runtime, database, etc.)

GitHub Vulnerability Alerts

CVE-2025-68480

Impact

Schema.load(data, many=True) is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time.

Patches

4.1.2, 3.26.2

Workarounds

# Fail fast
def load_many(schema, data, **kwargs):
    if not isinstance(data, list):
        raise ValidationError(['Invalid input type.'])
    return [schema.load(item, **kwargs) for item in data]

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Marshmallow has DoS in Schema.load(many)

CVE-2025-68480 / GHSA-428g-f7cq-pgp5

More information

Details

Impact

Schema.load(data, many=True) is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time.

Patches

4.1.2, 3.26.2

Workarounds

##### Fail fast
def load_many(schema, data, **kwargs):
    if not isinstance(data, list):
        raise ValidationError(['Invalid input type.'])
    return [schema.load(item, **kwargs) for item in data]

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

• https://github.com/marshmallow-code/marshmallow/security/advisories/GHSA-428g-f7cq-pgp5
• https://nvd.nist.gov/vuln/detail/CVE-2025-68480
• https://github.com/marshmallow-code/marshmallow/commit/d24a0c9df061c4daa92f71cf85aca25b83eee508
• https://github.com/marshmallow-code/marshmallow

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

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Release Notes

marshmallow-code/marshmallow (marshmallow)

v3.26.2

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Bug fixes:

• :cve:2025-68480: Merge error store messages without rebuilding collections.
  Thanks 카푸치노 for reporting and :user:deckar01 for the fix.

v3.26.1

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v3.26.0

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v3.25.1

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v3.25.0

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v3.24.2

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v3.24.1

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v3.24.0

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v3.23.3

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v3.23.2

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v3.23.1

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v3.23.0

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Configuration

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♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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This PR was generated by Mend Renovate. View the repository job log.

[notify-pr-bot]

⚠️ renovate-agent: The automated upgrade of marshmallow 3.22.0 → 3.26.2 failed the test suite.

The branch renovate-agent/marshmallow-3.26.2-20260327 has been deleted. A human should review the failure and either fix the code or manually skip this upgrade.

Workflow run: https://github.com/cds-snc/notification-api/actions/runs/23666223812