{"items":[{"id":"NVI-00018280","kind":"vulnerability","title":"Russh: Unchecked keyboard-interactive prompt count in client auth path","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-g9g7-5cgw-6v28","CVE-2026-48107"],"plain_summary":"GitHub lists this reviewed advisory for russh. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-0516f8c110a86340ff38736d672feefe"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-06-11T20:28:57.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-0516f8c110a86340ff38736d672feefe"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-0516f8c110a86340ff38736d672feefe","url":"https://github.com/advisories/GHSA-g9g7-5cgw-6v28","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-g9g7-5cgw-6v28","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T15:13:13.153Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0516f8c110a86340ff38736d672feefe"],"technology":"russh","known_exclusions":[],"conditions_summary":"### Summary\nIn the `russh` client keyboard-interactive authentication path, a malicious SSH server could send a `USERAUTH_INFO_REQUEST` with an attacker-controlled prompt count, and the client would use that raw count directly in `Vec::with_capacity(...)` before validating that enough prompt data was actually present in the packet.\n\nThis is a client-side denial-of-service / resource-exhaustion issue on the keyboard-interactive auth path.\n\n### Details\nThe vulnerable code path is in:\n\n- `russh/src/client/encrypted.rs`\n\nWhen the client is in `CurrentRequest::KeyboardInteractive` state and receives `SSH_MSG_USERAUTH_INFO_REQUEST`, it parses:\n\n1. `name`\n2. `instructions`\n3. `language tag`\n4. `n_prompts`\n\nBefore the fix, the code then did:\n\n```rust\nlet n_prompts = map_err!(u32::decode(&mut r))?;\nlet mut prompts = Vec::with_capacity(n_prompts.try_into().unwrap_or(0));\n```\n\nThat means a malicious server could advertise an enormous `n_prompts` value even if the packet contained no prompt bodies at all.\n\nThe fix rejects inconsistent prompt counts before allocating:\n\n```rust\nlet n_prompts = map_err!(u32::decode(&mut r))?;\nlet max_prompts = r.remaining_len() / 5;\nlet n_prompts = n_prompts as u","public_affected_ranges":[">= 0.37.0, < 0.61.0"]}],"null_published_at":"2026-11-07T07:07:39.800Z","source_updated_at":"2026-06-11T20:28:57.000Z","source_disclosed_at":"2026-06-11T20:28:56.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-06T15:13:13.153Z"}],"next_cursor":null,"snapshot_revision":"42594"}