Kayleen Fulton, a former Ethereum Foundation Protocol Support lead, has filed a lawsuit alleging she was fired shortly after disclosing a cancer diagnosis and challenging the Foundation’s employee mandate. The complaint, filed on November 4, 2026, in Colorado federal court, names the Ethereum Foundation, Vitalik Buterin and four other defendants.

Fulton alleges disability discrimination, retaliation and interference with medical leave rights. Her dismissal on April 6 followed a staff letter signed by 53 colleagues opposing controversial mandate conditions.

53 Employees Opposed Ethereum Foundation Mandate

The dispute began with the Ethereum Foundation Mandate, a document outlining the organization's direction and commitment to Ethereum principles. Its controversial Source Seppuku License included language requiring authors to “take his or her own life with a sword” for failing to uphold its pledges.

According to the lawsuit, 79 employees voted to remove the clause. Vitalik Buterin reportedly promised significant changes, but the final version retained the language in a stylized illustration. The Foundation subsequently recorded the mandate on the Ethereum blockchain.

Employees were also instructed to affirm their commitment to the mandate or leave. Fulton and colleague Trent Van Epps organized a letter signed by 53 staff members who supported the Foundation's objectives but objected to affirming the document under those conditions.

Kayleen Fulton Links Cancer Disclosure to April Firing

Fulton alleges she disclosed her cancer diagnosis to Foundation leadership on March 24 and requested that her employment status remain unchanged. She says management did not respond to her disclosure or discuss medical leave and accommodation.

The following day, Fulton and Van Epps circulated their employee letter. Both were dismissed on April 6, approximately 30 minutes apart, according to the complaint.

Fulton alleges her termination amounted to disability discrimination and retaliation for organizing opposition to the mandate. She also claims the Foundation interfered with her medical leave rights.

Her lawsuit states that she had previously received a strong performance assessment and a 21.9% salary increase in 2025. Fulton is seeking back pay, front pay and damages. The allegations have not been established in court.

Vitalik Buterin Named in Ethereum Foundation Lawsuit

Vitalik Buterin is named as a defendant because Fulton alleges he participated in adopting and enforcing the mandate related directive as a Foundation board member.

The complaint also references a May 1 conversation between Fulton and Buterin in Svalbard. According to the filing, Buterin discussed the consequences of rewarding employees for making a public or internal protest, saying that such outcomes could encourage others to use similar tactics to influence Foundation decisions.

Fulton interprets the remarks as relevant to her dismissal. However, the complaint does not establish that Buterin personally ordered her termination. It alleges that executive director Bastian Aue carried out the firing.

Ethereum Foundation Has Not Publicly Responded to Lawsuit

The lawsuit names six defendants, including the Foundation's Swiss and Singapore entities, two human resources companies, Bastian Aue and Vitalik Buterin.

A lawyer representing Ethereum Asia Pacific Limited, the Foundation's Singapore affiliate, previously denied unlawful conduct, retaliation and economic duress in a May 14 letter. The lawyer also maintained that Fulton's separation agreement was binding.

Fulton alleges she signed the agreement under pressure and subsequently rescinded it through legal counsel. She disputes its enforceability and challenges its Singapore arbitration provision.

As of November 10, 2026, the Foundation, Aue and Buterin had not publicly responded to the lawsuit. No court ruling has established whether the alleged discrimination or retaliation occurred.

The case places the Foundation's employee mandate, treatment of internal dissent and disability related employment practices under legal scrutiny. Its outcome remains pending.

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