
Hidden in Memory: Sleeper Memory Poisoning in LLM Agents
The paper discusses a new security risk associated with large language models that utilize persistent memory. It introduces the concept of sleeper memory poisoning, where adversaries can manipulate external contexts to implant false memories in the models. The study evaluates the effectiveness of this attack, revealing a high success rate in influencing future interactions with the models.
- ▪Sleeper memory poisoning allows adversaries to corrupt what an assistant remembers.
- ▪The attack can remain dormant and re-emerge in future conversations.
- ▪Poisoned memories were successfully added in up to 99.8% of cases on GPT-5.5.
- ▪Among successful retrievals, poisoned memories led to attacker-intended actions in 60-89% of evaluations.
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Story provenance
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Record
| Original publisher | arXiv cs.AI |
| Canonical URL | https://arxiv.org/abs/2605.15338 |
| Publication time | Mon, 18 May 2026 00:00:00 -0400 |
| Retrieval time | 2026-05-18T04:04:54.418Z |
| Last seen | 2026-05-18T04:04:54.418Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | b0ZGiaTO0Ih4 · 2 stories |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
Computer Science > Cryptography and Security arXiv:2605.15338 (cs) [Submitted on 14 May 2026] Title:Hidden in Memory: Sleeper Memory Poisoning in LLM Agents Authors:Sidharth Pulipaka, Stanislau Hlebik, Leonidas Raghav, Sahar Abdelnabi, Vyas Raina, Ivaxi Sheth, Mario Fritz View a PDF of the paper titled Hidden in Memory: Sleeper Memory Poisoning in LLM Agents, by Sidharth Pulipaka and 6 other authors View PDF HTML (experimental) Abstract:Large language models are increasingly augmented with persistent memory, allowing assistants to store user-specific information across sessions for personalization and continuity. This statefulness introduces a new security risk: adversarial content can corrupt what an assistant remembers and thereby influence future interactions.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at arXiv cs.AI.