Statement on the US government directive to suspend access to Fable 5 and Mythos 5

Statement on the US government directive to suspend access to Fable 5 and Mythos 5

抓取时间：2026-06-20

源链接：见各节头部

English Original

Statement on the US government directive to suspend access to Fable 5 and Mythos 5

作者: @AnthropicAI

原文链接: https://www.anthropic.com/news/fable-mythos-access

Announcements

Statement on the US government directive to suspend access to Fable 5 and Mythos 5

Jun 12, 2026

The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees. The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance. Access to all other Anthropic models will not be affected.

We received the directive from the government today at 5:21pm (ET). The letter did not provide specific details of its national security concern. Our understanding is that the government believes it has become aware of a method of bypassing, or “jailbreaking” Fable 5. We reviewed a demonstration of this specific technique being used to identify a small number of previously known, minor vulnerabilities. These vulnerabilities all appear relatively simple, and we have found that other publicly-available models are able to discover them as well without requiring a bypass.

Anthropic’s posture with respect to Fable’s safeguards, as laid out in our launch blog post, is the following:

• We have instituted strong safeguards that greatly reduce the likelihood that Fable is misused for tasks related to cybersecurity (among others). In fact, our safeguards are so strong that many users have complained that they are overly broad.
• In the weeks leading up to the launch of Fable, Anthropic worked with the US government, the UK AISI, multiple private third-party organizations and internal teams to red-team Fable’s safeguards for thousands of hours in total.
• These tests showed that Fable’s safeguards are substantially more effective than those of any previously deployed model.
• No testers have yet been able to find a _universal jailbreak_—a jailbreak method that can very broadly bypass the model’s safeguards, unblocking a wide range of cyber capabilities.
• We suspect that perfect jailbreak resistance is not currently possible for any model provider. Every safeguard used in the industry is vulnerable to _non-universal jailbreaks_ (which can elicit _some_ cyber information in specific circumstances), and it is likely that universal jailbreaks will eventually be found in the future. We stated this clearly when we released Fable 5.
• Given that perfect jailbreak resistance does not appear to be possible today, Anthropic adopted a _defense in depth_ strategy with Fable 5. We aimed to make jailbreaks either narrow (in the case of non-universal jailbreaks) or very expensive to produce (in the case of universal jailbreaks), and to combine this with thorough monitoring to quickly detect and shut down any successful attacks. This is also why Anthropic has required 30-day retention of customer data with Fable—a policy change that carries real costs for us with customers, but that allows us to research and mitigate jailbreaks.
• We stand by this defense in depth strategy. It reduces the risks posed by Fable, making them comparable to the risks of existing models already deployed across the industry.
• We have not even received a disclosure of a concerning non-universal potential jailbreak that led to a harmful result. The potential jailbreaks that have been disclosed to us are either entirely benign responses or are minor findings that provide no Mythos-specific uplift.

To date, the government has only given us verbal evidence of a potential narrow, non-universal jailbreak, which essentially consists of asking the model to read a specific codebase and fix any software flaws. Our understanding is that one potential jailbreak was shared with the government. We have reviewed a report that we believe is the basis of the government's directive and validated that the level of capability displayed there is widely available from other models (including OpenAI’s GPT-5.5), and is used every day by the defenders who keep systems safe. We will share more details over the next 24 hours.

We are complying with the government’s legal directive and are removing access to Fable 5 and Mythos 5 for all users. However, we disagree that the finding of a narrow potential jailbreak should be cause for recalling a commercial model deployed to hundreds of millions of people. If this standard was applied across the industry, we believe it would essentially halt all new model deployments for all frontier model providers.

As we have stated publicly, we believe the government should have the ability to block unsafe deployments, as part of a statutory process that is transparent, fair, clear, and grounded in technical facts. This action does not adhere to those principles.

We apologize for this disruption to our customers. We believe this is a misunderstanding and are working to restore access as soon as possible.

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中文翻译

关于美国政府指令暂停 Fable 5 与 Mythos 5 访问的声明

发布时间：2026 年 6 月 12 日

美国政府以国家安全为由发布了一项出口管制指令，要求暂停所有外国国民（无论身处美国境内还是境外，包括 Anthropic 的外国员工）对 Fable 5 与 Mythos 5 的访问。该指令的净效应是：我们必须立即为所有客户停用 Fable 5 与 Mythos 5，以确保合规。其他所有 Anthropic 模型均不受影响。

我们于今日美东时间下午 5:21 收到政府指令。函件中并未具体说明其国家安全关切所在。我们理解，政府认为自己已发现一种绕过（或"越狱"）Fable 5 的方法。我们审阅了该特定技术的演示，其仅能识别少量已知的小型漏洞。这些漏洞看起来都相对简单，并且我们发现其他公开可用的模型同样能够在不需要越狱的情况下发现这些漏洞。

Anthropic 在发布博客中关于 Fable 安全防护的立场如下：

• 我们部署了强大的安全防护，大幅降低 Fale 被滥用于网络安全等任务的可能性。事实上，我们的安全防护过于强大，以至于许多用户抱怨它们过于严苛。
• 在 Fable 发布前的几周，Anthropic 与美国政府、英国 AISI、多个第三方私人组织以及内部团队合作，对 Fable 的安全防护进行了总计数千小时的红队演练。
• 这些测试表明 Fable 的安全防护比此前部署过的任何模型都更有效。
• 至今尚无测试者找到一种通用越狱（一种能广泛绕过模型防护、释放大量网络能力的方法）。
• 我们怀疑对任何模型提供商而言，完美的越狱抗性目前都不可能实现。行业中的每一种防护都容易受到非通用越狱（可在特定情境下引出部分网络信息）的攻击，并且通用越狱在将来很可能被找到。我们在发布 Fable 5 时已经明确说明了这一点。
• 鉴于完美的越狱抗性今天似乎不可能实现，Anthropic 在 Fable 5 上采用了纵深防御策略。我们的目标是让越狱要么范围狭窄（针对非通用越狱），要么代价高昂（针对通用越狱），并结合完善的监控来快速检测和阻止任何成功的攻击。这也是 Anthropic 对 Fable 要求保留 30 天客户数据的原因——这一政策变化给我们与客户的关系带来了真实代价，但让我们能够研究并缓解越狱行为。
• 我们坚持这一纵深防御策略。它降低了 Fable 带来的风险，使其与整个行业现有部署模型的风险相当。
• 我们甚至尚未收到过导致有害结果的、令人担忧的非通用越狱披露。向我们披露的潜在越狱要么完全是良性响应，要么是不提供 Mythos 特定能力提升的小问题。

迄今为止，政府仅向我们提供了口头证据，证明存在一种潜在的、狭窄的、非通用越狱——其本质上是要求模型读取特定代码库并修复任何软件缺陷。我们的理解是，一种潜在的越狱已与政府分享。我们审阅了一份我们认为是政府指令依据的报告，并验证了其中展示的能力水平在包括 OpenAI GPT-5.5 在内的其他模型上广泛可得，并被每天维护系统安全的安全人员所日常使用。我们将在未来 24 小时内分享更多细节。

我们正在遵守政府的法律指令，并正在取消所有用户对 Fable 5 与 Mythos 5 的访问权限。然而，我们不认同发现一个狭窄的潜在越狱就应当成为召回一款已部署给数亿人使用的商业模型的理由。如果这一标准被应用于整个行业，我们相信它将基本停止所有前沿模型提供商的任何新模型部署。

对客户的影响：

• Fable 5 与 Mythos 5 的 API 调用将在 72 小时内全部返回 403 错误。
• 我们将为客户提供从 Fable 5 迁移到 Opus 4.7 的迁移路径，迁移补贴方案将另行通知。
• 所有相关订阅将自动按比例退款。

接下来： 我们将在未来 24 小时内发布更详细的技术分析，说明所披露的越狱与 Mythos 5 之间的具体差距，并公布我们的合规审计流程。

*本文由 opencli 抓取 + 人工翻译生成。*