diff --git a/core/internal/distros/debian_obs.go b/core/internal/distros/debian_obs.go
new file mode 100644
index 000000000..178f8dbc5
--- /dev/null
+++ b/core/internal/distros/debian_obs.go
@@ -0,0 +1,172 @@
+package distros
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	obsRepoDebian13       = "Debian_13"
+	obsRepoDebianTesting  = "Debian_Testing"
+	obsRepoDebianUnstable = "Debian_Unstable"
+)
+
+func debianOBSRepoVersion(info *OSInfo, aptSuites []string) string {
+	hasSuite := make(map[string]bool, len(aptSuites))
+	for _, suite := range aptSuites {
+		hasSuite[normalizeDebianSuite(suite)] = true
+	}
+
+	// APT suites distinguish testing from sid. os-release cannot: both currently
+	// report VERSION_CODENAME=forky and PRETTY_NAME="Debian GNU/Linux forky/sid"
+	if hasSuite["sid"] || hasSuite["unstable"] {
+		return obsRepoDebianUnstable
+	}
+	if hasSuite["testing"] || hasSuite["forky"] {
+		return obsRepoDebianTesting
+	}
+	if hasSuite["trixie"] || hasSuite["stable"] {
+		return obsRepoDebian13
+	}
+
+	if info == nil {
+		return obsRepoDebian13
+	}
+
+	id := strings.ToLower(strings.TrimSpace(info.VersionID))
+	code := strings.ToLower(strings.TrimSpace(info.VersionCodename))
+
+	if code == "sid" || id == "sid" {
+		return obsRepoDebianUnstable
+	}
+	if id == "13" || code == "trixie" {
+		return obsRepoDebian13
+	}
+	if id != "" && id != "testing" {
+		return obsRepoDebian13
+	}
+	// Prefer Testing when os-release is the shared forky/sid string. Unstable
+	// OBS packages can require a newer glibc than Testing ships.
+	return obsRepoDebianTesting
+}
+
+func debianOBSListFileMatches(path, debianVersion string) bool {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return false
+	}
+	return debianOBSListPointsAt(string(data), debianVersion)
+}
+
+func debianOBSListPointsAt(contents, debianVersion string) bool {
+	return strings.Contains(contents, "/"+debianVersion+"/")
+}
+
+func readDebianAPTSuites() []string {
+	var chunks []string
+	if data, err := os.ReadFile("/etc/apt/sources.list"); err == nil {
+		chunks = append(chunks, string(data))
+	}
+	matches, _ := filepath.Glob("/etc/apt/sources.list.d/*")
+	for _, path := range matches {
+		if !strings.HasSuffix(path, ".list") && !strings.HasSuffix(path, ".sources") {
+			continue
+		}
+		data, err := os.ReadFile(path)
+		if err != nil {
+			continue
+		}
+		chunks = append(chunks, string(data))
+	}
+	return debianAPTSuites(strings.Join(chunks, "\n"))
+}
+
+func debianAPTSuites(sources string) []string {
+	seen := make(map[string]bool)
+	var suites []string
+	add := func(raw string) {
+		suite := normalizeDebianSuite(raw)
+		if suite == "" || seen[suite] {
+			return
+		}
+		seen[suite] = true
+		suites = append(suites, suite)
+	}
+
+	var stanza []string
+	flushStanza := func() {
+		if len(stanza) == 0 {
+			return
+		}
+		enabled := true
+		var stanzaSuites []string
+		for _, line := range stanza {
+			key, val, ok := strings.Cut(line, ":")
+			if !ok {
+				continue
+			}
+			switch strings.ToLower(strings.TrimSpace(key)) {
+			case "enabled":
+				switch strings.ToLower(strings.TrimSpace(val)) {
+				case "no", "false", "0":
+					enabled = false
+				}
+			case "suites":
+				stanzaSuites = strings.Fields(val)
+			}
+		}
+		if enabled {
+			for _, suite := range stanzaSuites {
+				add(suite)
+			}
+		}
+		stanza = nil
+	}
+
+	for _, raw := range strings.Split(sources, "\n") {
+		line := strings.TrimSpace(raw)
+		if line == "" {
+			flushStanza()
+			continue
+		}
+		if strings.HasPrefix(line, "#") {
+			continue
+		}
+		lower := strings.ToLower(line)
+		if strings.HasPrefix(lower, "deb ") || strings.HasPrefix(lower, "deb-src ") {
+			flushStanza()
+			if suite := suiteFromDebLine(line); suite != "" {
+				add(suite)
+			}
+			continue
+		}
+		stanza = append(stanza, line)
+	}
+	flushStanza()
+	return suites
+}
+
+func suiteFromDebLine(line string) string {
+	if i := strings.Index(line, "["); i != -1 {
+		if j := strings.Index(line, "]"); j > i {
+			line = strings.TrimSpace(line[:i] + " " + line[j+1:])
+		}
+	}
+	fields := strings.Fields(line)
+	if len(fields) < 3 {
+		return ""
+	}
+	return fields[2]
+}
+
+func normalizeDebianSuite(suite string) string {
+	suite = strings.ToLower(strings.TrimSpace(suite))
+	suite = strings.Trim(suite, "/")
+	for _, suffix := range []string{"-security", "-updates", "-backports", "-proposed-updates"} {
+		if strings.HasSuffix(suite, suffix) {
+			return strings.TrimSuffix(suite, suffix)
+		}
+	}
+	return suite
+}