diff --git a/Cargo.lock b/Cargo.lock
index 280e7f4..f8a6d02 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5089,6 +5089,12 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "sha1_smol"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbfa15b3dddfee50a0fff136974b3e1bde555604ba463834a7eb7deb6417705d"
+
 [[package]]
 name = "sha2"
 version = "0.10.9"
@@ -6472,6 +6478,7 @@ dependencies = [
  "getrandom 0.4.1",
  "js-sys",
  "serde_core",
+ "sha1_smol",
  "wasm-bindgen",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 7ea8120..e8cb61b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,7 +28,7 @@ reqwest = { version = "0.12", features = ["json", "rustls-tls", "multipart", "co
 thiserror = "2"
 sha2 = "0.10"
 hex = "0.4"
-uuid = { version = "1", features = ["v4", "serde"] }
+uuid = { version = "1", features = ["v4", "v5", "serde"] }
 secrecy = { version = "0.10", features = ["serde"] }
 regex = "1"
 zip = { version = "2", features = ["aes-crypto", "deflate"] }
diff --git a/compliance-core/src/models/mod.rs b/compliance-core/src/models/mod.rs
index 926dd78..b850955 100644
--- a/compliance-core/src/models/mod.rs
+++ b/compliance-core/src/models/mod.rs
@@ -11,6 +11,7 @@ pub mod mcp_token;
 pub mod notification;
 pub mod onboarding;
 pub mod oscal;
+pub mod oscal_assessment;
 pub mod pentest;
 pub mod repository;
 pub mod sbom;
@@ -41,6 +42,7 @@ pub use onboarding::{
     TargetScanConfig, TargetType, TargetTypeCandidate, WebArtifactConfig,
 };
 pub use oscal::OscalDocument;
+pub use oscal_assessment::{assess, AssessmentResultsDoc, ControlLinker};
 pub use pentest::{
     AttackChainNode, AttackNodeStatus, AuthMode, CodeContextHint, Environment, IdentityProvider,
     PentestAuthConfig, PentestConfig, PentestEvent, PentestMessage, PentestSession, PentestStats,
diff --git a/compliance-core/src/models/oscal_assessment.rs b/compliance-core/src/models/oscal_assessment.rs
new file mode 100644
index 0000000..f78ea6d
--- /dev/null
+++ b/compliance-core/src/models/oscal_assessment.rs
@@ -0,0 +1,402 @@
+//! OSCAL 1.1 assessment-results — assess our findings against catalog controls.
+//!
+//! The catalog (domain content) comes from the producer; the **assessment** is
+//! ours. This links compliance [`Finding`]s to catalog control-ids and emits a
+//! standard OSCAL assessment-results document: an observation per linked finding,
+//! and a per-control finding with a `not-satisfied` status. `reviewed-controls`
+//! records the full catalog set we considered.
+//!
+//! Deterministic: stable `uuid5` ids; the caller supplies the assessment
+//! timestamp. Pure — no DB, no network.
+
+use std::collections::HashMap;
+
+use chrono::{DateTime, Utc};
+use serde::Serialize;
+use uuid::Uuid;
+
+use crate::models::finding::Finding;
+use crate::traits::Control;
+
+const OSCAL_VERSION: &str = "1.1.2";
+/// Same namespace as the catalog exporter, so ids are stable and correlatable.
+const NAMESPACE: Uuid = Uuid::from_bytes([
+    0x6f, 0x1e, 0x7c, 0x2a, 0x3b, 0x4d, 0x5e, 0x6f, 0x8a, 0x9b, 0x0c, 0x1d, 0x2e, 0x3f, 0x4a, 0x5b,
+]);
+
+fn det_uuid(name: &str) -> String {
+    Uuid::new_v5(&NAMESPACE, name.as_bytes()).to_string()
+}
+
+/// Links findings to the catalog control-ids they provide evidence for.
+pub struct ControlLinker {
+    cwe_to_controls: HashMap<u32, Vec<String>>,
+}
+
+impl ControlLinker {
+    /// Build a linker from an explicit CWE → control-id map.
+    pub fn new(cwe_to_controls: HashMap<u32, Vec<String>>) -> Self {
+        Self { cwe_to_controls }
+    }
+
+    /// Seed of CWE → CRA Annex I control mappings (mirrors breakpilot's
+    /// `_CWE_TO_REQ`; extend as scanner coverage grows).
+    pub fn cra_seed() -> Self {
+        let pairs: &[(u32, &str)] = &[
+            (798, "cra-ai-8"),
+            (259, "cra-ai-8"),
+            (1392, "cra-ai-8"),
+            (327, "cra-ai-13"),
+            (326, "cra-ai-13"),
+            (319, "cra-ai-15"),
+            (311, "cra-ai-15"),
+            (89, "cra-ai-20"),
+            (79, "cra-ai-20"),
+            (78, "cra-ai-20"),
+            (22, "cra-ai-20"),
+        ];
+        let mut map: HashMap<u32, Vec<String>> = HashMap::new();
+        for (cwe, id) in pairs {
+            map.entry(*cwe).or_default().push((*id).to_string());
+        }
+        Self::new(map)
+    }
+
+    /// Parse a CWE token such as `"CWE-798"` or `"798"` into its number.
+    fn parse_cwe(raw: &str) -> Option<u32> {
+        raw.trim_start_matches(|c: char| !c.is_ascii_digit())
+            .split(|c: char| !c.is_ascii_digit())
+            .next()
+            .filter(|s| !s.is_empty())
+            .and_then(|s| s.parse().ok())
+    }
+
+    /// The control-ids a finding provides evidence for (via its CWE).
+    pub fn controls_for(&self, finding: &Finding) -> Vec<String> {
+        finding
+            .cwe
+            .as_deref()
+            .and_then(Self::parse_cwe)
+            .and_then(|cwe| self.cwe_to_controls.get(&cwe))
+            .cloned()
+            .unwrap_or_default()
+    }
+}
+
+/// Assess `findings` against `controls`: link findings to control-ids and build a
+/// standard OSCAL assessment-results document. `at` is the assessment timestamp.
+pub fn assess(
+    controls: &[Control],
+    findings: &[Finding],
+    linker: &ControlLinker,
+    at: DateTime<Utc>,
+) -> AssessmentResultsDoc {
+    let ts = at.to_rfc3339();
+
+    let mut observations = Vec::new();
+    let mut obs_by_control: HashMap<String, Vec<String>> = HashMap::new();
+    for finding in findings {
+        let targets = linker.controls_for(finding);
+        if targets.is_empty() {
+            continue;
+        }
+        let obs_uuid = det_uuid(&format!("obs:{}", finding.fingerprint));
+        let location = match (&finding.file_path, finding.line_number) {
+            (Some(f), Some(l)) => Some(format!("{f}:{l}")),
+            (Some(f), None) => Some(f.clone()),
+            _ => None,
+        };
+        observations.push(Observation {
+            uuid: obs_uuid.clone(),
+            description: finding.title.clone(),
+            methods: vec!["TEST".to_string()],
+            collected: ts.clone(),
+            relevant_evidence: vec![RelevantEvidence {
+                href: location.map(|l| format!("file://{l}")),
+                description: format!("[{}] {}", finding.scanner, finding.title),
+            }],
+        });
+        for control_id in targets {
+            obs_by_control
+                .entry(control_id)
+                .or_default()
+                .push(obs_uuid.clone());
+        }
+    }
+
+    let titles: HashMap<&str, &str> = controls
+        .iter()
+        .map(|c| (c.id.as_str(), c.title.as_str()))
+        .collect();
+    let mut hit_controls: Vec<&String> = obs_by_control.keys().collect();
+    hit_controls.sort();
+    let ar_findings: Vec<ArFinding> = hit_controls
+        .into_iter()
+        .map(|control_id| {
+            let title = titles.get(control_id.as_str()).copied().unwrap_or("");
+            ArFinding {
+                uuid: det_uuid(&format!("finding:{control_id}")),
+                title: format!("Findings affect {control_id}: {title}"),
+                target: FindingTarget {
+                    target_type: "statement-id".to_string(),
+                    target_id: format!("{control_id}_smt"),
+                    status: TargetStatus {
+                        state: "not-satisfied".to_string(),
+                    },
+                },
+                related_observations: obs_by_control[control_id]
+                    .iter()
+                    .map(|u| RelatedObservation {
+                        observation_uuid: u.clone(),
+                    })
+                    .collect(),
+            }
+        })
+        .collect();
+
+    let include_controls = controls
+        .iter()
+        .map(|c| SelectControlById {
+            control_id: c.id.clone(),
+        })
+        .collect();
+
+    let result = ArResult {
+        uuid: det_uuid("result:cra"),
+        title: "Automated code-compliance assessment".to_string(),
+        description: format!(
+            "{} finding-linked observation(s) across {} reviewed control(s)",
+            observations.len(),
+            controls.len()
+        ),
+        start: ts.clone(),
+        reviewed_controls: ReviewedControls {
+            control_selections: vec![ControlSelection { include_controls }],
+        },
+        observations,
+        findings: ar_findings,
+    };
+
+    AssessmentResultsDoc {
+        assessment_results: AssessmentResults {
+            uuid: det_uuid("assessment-results:cra"),
+            metadata: ArMetadata {
+                title: "Compliance scanner — OSCAL assessment results".to_string(),
+                last_modified: ts,
+                version: "1.0.0".to_string(),
+                oscal_version: OSCAL_VERSION.to_string(),
+            },
+            import_ap: ImportAp {
+                href: "#cra-annex-i".to_string(),
+            },
+            results: vec![result],
+        },
+    }
+}
+
+// ── OSCAL assessment-results document (serialise) ────────────────────────────
+
+/// The root OSCAL assessment-results document.
+#[derive(Debug, Clone, Serialize)]
+pub struct AssessmentResultsDoc {
+    #[serde(rename = "assessment-results")]
+    pub assessment_results: AssessmentResults,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct AssessmentResults {
+    pub uuid: String,
+    pub metadata: ArMetadata,
+    #[serde(rename = "import-ap")]
+    pub import_ap: ImportAp,
+    pub results: Vec<ArResult>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArMetadata {
+    pub title: String,
+    #[serde(rename = "last-modified")]
+    pub last_modified: String,
+    pub version: String,
+    #[serde(rename = "oscal-version")]
+    pub oscal_version: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ImportAp {
+    pub href: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArResult {
+    pub uuid: String,
+    pub title: String,
+    pub description: String,
+    pub start: String,
+    #[serde(rename = "reviewed-controls")]
+    pub reviewed_controls: ReviewedControls,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub observations: Vec<Observation>,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub findings: Vec<ArFinding>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ReviewedControls {
+    #[serde(rename = "control-selections")]
+    pub control_selections: Vec<ControlSelection>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ControlSelection {
+    #[serde(rename = "include-controls", skip_serializing_if = "Vec::is_empty")]
+    pub include_controls: Vec<SelectControlById>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct SelectControlById {
+    #[serde(rename = "control-id")]
+    pub control_id: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct Observation {
+    pub uuid: String,
+    pub description: String,
+    pub methods: Vec<String>,
+    pub collected: String,
+    #[serde(rename = "relevant-evidence", skip_serializing_if = "Vec::is_empty")]
+    pub relevant_evidence: Vec<RelevantEvidence>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct RelevantEvidence {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub href: Option<String>,
+    pub description: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ArFinding {
+    pub uuid: String,
+    pub title: String,
+    pub target: FindingTarget,
+    #[serde(rename = "related-observations", skip_serializing_if = "Vec::is_empty")]
+    pub related_observations: Vec<RelatedObservation>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct FindingTarget {
+    #[serde(rename = "type")]
+    pub target_type: String,
+    #[serde(rename = "target-id")]
+    pub target_id: String,
+    pub status: TargetStatus,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct TargetStatus {
+    pub state: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct RelatedObservation {
+    #[serde(rename = "observation-uuid")]
+    pub observation_uuid: String,
+}
+
+#[cfg(test)]
+#[allow(clippy::unwrap_used)]
+mod tests {
+    use super::*;
+    use crate::models::finding::Severity;
+    use crate::models::onboarding::ComplianceFramework;
+    use crate::models::scan::ScanType;
+
+    fn control(id: &str, title: &str) -> Control {
+        Control {
+            id: id.into(),
+            framework: ComplianceFramework::Cra,
+            title: title.into(),
+            text: String::new(),
+            source: None,
+        }
+    }
+
+    fn finding(fp: &str, cwe: Option<&str>) -> Finding {
+        let mut f = Finding::new(
+            "repo".into(),
+            fp.into(),
+            "semgrep".into(),
+            ScanType::Sast,
+            "hardcoded credential".into(),
+            "desc".into(),
+            Severity::High,
+        );
+        f.cwe = cwe.map(Into::into);
+        f.file_path = Some("src/auth.rs".into());
+        f.line_number = Some(42);
+        f
+    }
+
+    fn at() -> DateTime<Utc> {
+        DateTime::parse_from_rfc3339("2026-07-20T00:00:00Z")
+            .unwrap()
+            .with_timezone(&Utc)
+    }
+
+    #[test]
+    fn links_cwe_finding_to_control_not_satisfied() {
+        let controls = vec![
+            control("cra-ai-8", "No default passwords"),
+            control("cra-ai-13", "Crypto"),
+        ];
+        let findings = vec![finding("f1", Some("CWE-798"))];
+        let doc = assess(&controls, &findings, &ControlLinker::cra_seed(), at());
+        let r = &doc.assessment_results.results[0];
+        assert_eq!(r.observations.len(), 1);
+        assert_eq!(r.findings.len(), 1);
+        assert_eq!(r.findings[0].target.target_id, "cra-ai-8_smt");
+        assert_eq!(r.findings[0].target.status.state, "not-satisfied");
+        assert_eq!(r.findings[0].related_observations.len(), 1);
+        assert_eq!(
+            r.reviewed_controls.control_selections[0]
+                .include_controls
+                .len(),
+            2
+        );
+    }
+
+    #[test]
+    fn unlinked_finding_yields_no_control_finding() {
+        let controls = vec![control("cra-ai-8", "x")];
+        let findings = vec![finding("f1", Some("CWE-99999"))];
+        let doc = assess(&controls, &findings, &ControlLinker::cra_seed(), at());
+        let r = &doc.assessment_results.results[0];
+        assert!(r.observations.is_empty());
+        assert!(r.findings.is_empty());
+    }
+
+    #[test]
+    fn output_is_deterministic_and_valid_oscal() {
+        let controls = vec![control("cra-ai-8", "x")];
+        let findings = vec![finding("f1", Some("798"))];
+        let a = serde_json::to_string(&assess(
+            &controls,
+            &findings,
+            &ControlLinker::cra_seed(),
+            at(),
+        ))
+        .unwrap();
+        let b = serde_json::to_string(&assess(
+            &controls,
+            &findings,
+            &ControlLinker::cra_seed(),
+            at(),
+        ))
+        .unwrap();
+        assert_eq!(a, b);
+        assert!(a.contains("\"oscal-version\":\"1.1.2\""));
+        assert!(a.contains("\"not-satisfied\""));
+    }
+}