How do I check whether I am affected by CVE-2026-95183?

You are exposed if you run dsh from a source checkout at or after master commit c291e796 (git log) with the compaction-basic package enabled (packages/compaction/compaction-basic) and the agent reads untrusted content (web, email, repo files, tickets). Dangerous mainly where the agent has shell or network tools. Review the compaction summary before resuming a long session.

What is the fix for CVE-2026-95183?

No fixed commit or version published as of 2026-10-23. Mitigate: do not let dsh read untrusted content in long sessions, disable or avoid auto-compaction, inspect compacted summaries before resuming, restrict network egress and shell tools. Watch deepseek-ai/deepseek-harness for a fix.

Who is not affected by CVE-2026-95183?

Not affected if: compaction-disabled, no-untrusted-content, not-source-checkout, unknown.

Live › vulnerability › CVE-2026-95183

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high8.8AI agents & MCP

DeepSeek Harness: crafted content during context compaction enables prompt injection

DeepSeek Harness (dsh, developer preview) compaction is model-written: the summarizer in @deepseek-ai/dsh-compaction-basic copies instructions injected in tool output (web pages, email, repo files) verbatim into the checkpoint's Primary Request, Pending Jobs and Critical Context sections. The resumed session inherits them as its own tasks, and the user is never shown the summary. Tested on master commit c291e796 (2026-09). In the researcher's test the resumed model refused to run the injected shell command, but the payload persisted every time. Network egress is unrestricted, so silent exfiltration is the practical risk. No fix or vendor response is published.

Summary written from the sources below. Check the originals before acting.

CVSS 3.x

8.8

high

scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0

known so far6 of 6

First public: Oct 16, 2026 UTC
Last modified: Oct 23, 2026
Status: open
Known exploitation: None reported
Public exploit: 1 PoC repo on GitHub
EPSS: not scored

First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.

Why it is high, and not just CVSS

Likelihood → · Impact ↓

critical

high

medium

high

medium

low

medium

low

Exploited: Yes, proof of concept public on GitHub.
Needs login: Not known from the sources.
Needs a special setup: Not known from the sources.
Reachable from: Not known from the sources.
Worst case: Attacker steers the agent via injected prompts from external content.
CVSS said: 8.8. The facts above say critical; we keep the sources' high until an analyst looks.

Who is affected

1 product

Know the next one before it finds you.

Add to Slack

Live › vulnerability › CVE-2026-95183

Go to dashboard

high8.8AI agents & MCP

DeepSeek Harness: crafted content during context compaction enables prompt injection

Summary written from the sources below. Check the originals before acting.

CVSS 3.x

8.8

high

scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0

known so far6 of 6

First public: Oct 16, 2026 UTC
Last modified: Oct 23, 2026
Status: open
Known exploitation: None reported
Public exploit: 1 PoC repo on GitHub
EPSS: not scored

First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.

Why it is high, and not just CVSS

Likelihood → · Impact ↓

critical

high

medium

high

medium

low

medium

low

Exploited: Yes, proof of concept public on GitHub.
Needs login: Not known from the sources.
Needs a special setup: Not known from the sources.
Reachable from: Not known from the sources.
Worst case: Attacker steers the agent via injected prompts from external content.
CVSS said: 8.8. The facts above say critical; we keep the sources' high until an analyst looks.

Who is affected

1 product

Know the next one before it finds you.

Add to Slack

DeepSeek Harness: crafted content during context compaction enables prompt injection

Why it is high, and not just CVSS

Who is affected

Know the next one before it finds you.

DeepSeek Harness: crafted content during context compaction enables prompt injection

Why it is high, and not just CVSS

Who is affected

Know the next one before it finds you.

How to check

The fix

Who had it, and when

What the sources say, verbatim

Sources