diff --git a/cmd/api/src/api/auth.go b/cmd/api/src/api/auth.go
index 3f30c4afb..9655a6af4 100644
--- a/cmd/api/src/api/auth.go
+++ b/cmd/api/src/api/auth.go
@@ -296,24 +296,23 @@ func (s authenticator) ValidateRequestSignature(tokenID uuid.UUID, request *http
 }
 
 func DeleteBrowserCookie(request *http.Request, response http.ResponseWriter, name string) {
-	SetSecureBrowserCookie(request, response, name, "", time.Now().UTC(), false)
+	SetSecureBrowserCookie(request, response, name, "", time.Now().UTC(), false, 0)
 }
 
-func SetSecureBrowserCookie(request *http.Request, response http.ResponseWriter, name, value string, expires time.Time, httpOnly bool) {
+func SetSecureBrowserCookie(request *http.Request, response http.ResponseWriter, name, value string, expires time.Time, httpOnly bool, sameSite http.SameSite) {
 	var (
-		hostURL       = *ctx.FromRequest(request).Host
-		sameSiteValue = http.SameSiteDefaultMode
-		domainValue   string
+		hostURL = *ctx.FromRequest(request).Host
+		isHttps = hostURL.Scheme == "https"
 	)
 
-	if hostURL.Scheme == "https" {
-		sameSiteValue = http.SameSiteStrictMode
+	// If sameSite is not explicitly set, we want to rely on the host scheme
+	if sameSite == 0 && isHttps {
+		sameSite = http.SameSiteStrictMode
 	}
 
-	// NOTE: Set-Cookie should generally have the Domain field blank to ensure the cookie is only included with requests against the host, excluding subdomains; however,
-	// most browsers will ignore Set-Cookie headers from localhost responses if the Domain field is not set explicitly.
-	if strings.Contains(hostURL.Hostname(), "localhost") {
-		domainValue = hostURL.Hostname()
+	// NOTE: Browsers will not set localhost cookies with sameSite set to None. This is a local network SSO workaround
+	if strings.Contains(hostURL.Hostname(), "localhost") && sameSite == http.SameSiteNoneMode {
+		sameSite = http.SameSiteDefaultMode
 	}
 
 	// Set the token cookie
@@ -321,11 +320,10 @@ func SetSecureBrowserCookie(request *http.Request, response http.ResponseWriter,
 		Name:     name,
 		Value:    value,
 		Expires:  expires,
-		Secure:   hostURL.Scheme == "https",
+		Secure:   isHttps,
 		HttpOnly: httpOnly,
-		SameSite: sameSiteValue,
+		SameSite: sameSite,
 		Path:     "/",
-		Domain:   domainValue,
 	})
 }
 
@@ -356,8 +354,6 @@ func (s authenticator) CreateSSOSession(request *http.Request, response http.Res
 			auditLogFields["oidc_provider_id"] = ssoProvider.OIDCProvider.ID
 			authProvider = *ssoProvider.OIDCProvider
 		}
-		DeleteBrowserCookie(request, response, AuthStateCookieName)
-		DeleteBrowserCookie(request, response, AuthPKCECookieName)
 	}
 
 	// Generate commit ID for audit logging
@@ -404,8 +400,8 @@ func (s authenticator) CreateSSOSession(request *http.Request, response http.Res
 
 			locationURL := URLJoinPath(hostURL, UserInterfacePath)
 
-			// Set the token cookie
-			SetSecureBrowserCookie(request, response, AuthTokenCookieName, sessionJWT, time.Now().UTC().Add(s.cfg.AuthSessionTTL()), false)
+			// Set the token cookie, httpOnly must be false for the UI to pick up and store token
+			SetSecureBrowserCookie(request, response, AuthTokenCookieName, sessionJWT, time.Now().UTC().Add(s.cfg.AuthSessionTTL()), false, 0)
 
 			// Redirect back to the UI landing page
 			response.Header().Add(headers.Location.String(), locationURL.String())
diff --git a/cmd/api/src/api/constant.go b/cmd/api/src/api/constant.go
index 1fe172b81..0eab516f3 100644
--- a/cmd/api/src/api/constant.go
+++ b/cmd/api/src/api/constant.go
@@ -34,14 +34,16 @@ const (
 	AuthorizationSchemeBHESignature = "bhesignature"
 	AuthorizationSchemeBearer       = "bearer"
 
+	// Form parameters
+	FormParameterState = "state"
+	FormParameterCode  = "code"
+
 	// Query parameters
 	QueryParameterSortBy         = "sort_by"
 	QueryParameterHydrateCounts  = "counts"
 	QueryParameterHydrateDomains = "hydrate_domains"
 	QueryParameterHydrateOUs     = "hydrate_ous"
 	QueryParameterScope          = "scope"
-	QueryParameterState          = "state"
-	QueryParameterCode           = "code"
 
 	// URI path parameters
 	URIPathVariableApplicationConfigurationParameter = "parameter"
diff --git a/cmd/api/src/api/v2/auth/oidc.go b/cmd/api/src/api/v2/auth/oidc.go
index 69fb644f2..3a6c78e94 100644
--- a/cmd/api/src/api/v2/auth/oidc.go
+++ b/cmd/api/src/api/v2/auth/oidc.go
@@ -183,14 +183,13 @@ func (s ManagementResource) OIDCLoginHandler(response http.ResponseWriter, reque
 		verifier := oauth2.GenerateVerifier()
 
 		// Store PKCE on web browser in secure cookie for retrieval in callback
-		api.SetSecureBrowserCookie(request, response, api.AuthPKCECookieName, verifier, time.Now().UTC().Add(time.Minute*7), true)
+		api.SetSecureBrowserCookie(request, response, api.AuthPKCECookieName, verifier, time.Now().UTC().Add(time.Minute*7), true, http.SameSiteNoneMode)
 
 		// Store State on web browser in secure cookie for retrieval in callback
-		api.SetSecureBrowserCookie(request, response, api.AuthStateCookieName, state, time.Now().UTC().Add(time.Minute*7), true)
-
-		// Redirect user to consent page to ask for permission for the scopes specified above.
-		redirectURL := conf.AuthCodeURL(state, oauth2.AccessTypeOffline, oauth2.S256ChallengeOption(verifier))
+		api.SetSecureBrowserCookie(request, response, api.AuthStateCookieName, state, time.Now().UTC().Add(time.Minute*7), true, http.SameSiteNoneMode)
 
+		// Redirect user to consent page to ask for permission for the scopes specified above and specify POST callback
+		redirectURL := conf.AuthCodeURL(state, oauth2.AccessTypeOffline, oauth2.S256ChallengeOption(verifier), oauth2.SetAuthURLParam("response_mode", "form_post"))
 		response.Header().Add(headers.Location.String(), redirectURL)
 		response.WriteHeader(http.StatusFound)
 	}
@@ -198,39 +197,37 @@ func (s ManagementResource) OIDCLoginHandler(response http.ResponseWriter, reque
 
 func (s ManagementResource) OIDCCallbackHandler(response http.ResponseWriter, request *http.Request, ssoProvider model.SSOProvider) {
 	var (
-		queryParams = request.URL.Query()
-		state       = queryParams[api.QueryParameterState]
-		code        = queryParams[api.QueryParameterCode]
+		state = request.FormValue(api.FormParameterState)
+		code  = request.FormValue(api.FormParameterCode)
 	)
 
+	// No matter what happens, wipe the auth cookies
+	api.DeleteBrowserCookie(request, response, api.AuthStateCookieName)
+	api.DeleteBrowserCookie(request, response, api.AuthPKCECookieName)
+
 	if ssoProvider.OIDCProvider == nil {
 		// SSO misconfiguration scenario
 		api.RedirectToLoginURL(response, request, "Your SSO Connection failed, please contact your Administrator")
-	} else if len(code) == 0 {
-		// Don't want to log state but do want to know if state was present
-		hasState := queryParams.Has(api.QueryParameterState)
-		queryParams.Del(api.QueryParameterState)
-		log.Warnf("[OIDC] auth code is missing, has state %t %+v", hasState, queryParams)
-		// Missing authorization code implies a credentials or form issue
-		// Not explicitly covered, treat as technical issue
+	} else if code == "" {
+		log.Warnf("[OIDC] auth code is missing")
+		api.RedirectToLoginURL(response, request, "We’re having trouble connecting. Please check your internet and try again.")
+	} else if state == "" {
+		log.Warnf("[OIDC] state parameter is missing")
+		// Missing state parameter - treat as technical issue
 		api.RedirectToLoginURL(response, request, "We’re having trouble connecting. Please check your internet and try again.")
 	} else if pkceVerifier, err := request.Cookie(api.AuthPKCECookieName); err != nil {
 		log.Warnf("[OIDC] pkce cookie is missing")
 		// Missing PKCE verifier - likely a technical or config issue
 		api.RedirectToLoginURL(response, request, "We’re having trouble connecting. Please check your internet and try again.")
-	} else if len(state) == 0 {
-		log.Warnf("[OIDC] state parameter is missing")
-		// Missing state parameter - treat as technical issue
-		api.RedirectToLoginURL(response, request, "We’re having trouble connecting. Please check your internet and try again.")
-	} else if stateCookie, err := request.Cookie(api.AuthStateCookieName); err != nil || stateCookie.Value != state[0] {
-		log.Warnf("[OIDC] state cookie does not match %v", err)
+	} else if stateCookie, err := request.Cookie(api.AuthStateCookieName); err != nil || stateCookie.Value != state {
+		log.Warnf(fmt.Sprintf("[OIDC] state cookie does not match %v", err))
 		// Invalid state - treat as technical issue or misconfiguration
 		api.RedirectToLoginURL(response, request, "We’re having trouble connecting. Please check your internet and try again.")
 	} else if provider, err := oidc.NewProvider(request.Context(), ssoProvider.OIDCProvider.Issuer); err != nil {
 		log.Warnf("[OIDC] Failed to create OIDC provider: %v", err)
 		// SSO misconfiguration scenario
 		api.RedirectToLoginURL(response, request, "Your SSO Connection failed, please contact your Administrator")
-	} else if claims, err := getOIDCClaims(request.Context(), provider, ssoProvider, pkceVerifier, code[0]); err != nil {
+	} else if claims, err := getOIDCClaims(request.Context(), provider, ssoProvider, pkceVerifier, code); err != nil {
 		log.Warnf("[OIDC] %v", err)
 		api.RedirectToLoginURL(response, request, "Your SSO was unable to authenticate your user, please contact your Administrator")
 	} else if email, err := getEmailFromOIDCClaims(claims); errors.Is(err, ErrEmailMissing) { // Note email claims are not always present so we will check different claim keys for possible email