diff --git a/apps/sim/app/api/tools/confluence/page-descendants/route.ts b/apps/sim/app/api/tools/confluence/page-descendants/route.ts
index ecdc500591..e437b73750 100644
--- a/apps/sim/app/api/tools/confluence/page-descendants/route.ts
+++ b/apps/sim/app/api/tools/confluence/page-descendants/route.ts
@@ -1,7 +1,11 @@
 import { createLogger } from '@sim/logger'
 import { type NextRequest, NextResponse } from 'next/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
-import { validateAlphanumericId, validateJiraCloudId } from '@/lib/core/security/input-validation'
+import {
+  validateAlphanumericId,
+  validateJiraCloudId,
+  validatePaginationCursor,
+} from '@/lib/core/security/input-validation'
 import { getConfluenceCloudId } from '@/tools/confluence/utils'
 
 const logger = createLogger('ConfluencePageDescendantsAPI')
@@ -50,6 +54,10 @@ export async function POST(request: NextRequest) {
     queryParams.append('limit', String(Math.min(limit, 250)))
 
     if (cursor) {
+      const cursorValidation = validatePaginationCursor(cursor, 'cursor')
+      if (!cursorValidation.isValid) {
+        return NextResponse.json({ error: cursorValidation.error }, { status: 400 })
+      }
       queryParams.append('cursor', cursor)
     }
 
diff --git a/apps/sim/app/api/tools/confluence/page-versions/route.ts b/apps/sim/app/api/tools/confluence/page-versions/route.ts
index cdd77f4e76..799fc28b0a 100644
--- a/apps/sim/app/api/tools/confluence/page-versions/route.ts
+++ b/apps/sim/app/api/tools/confluence/page-versions/route.ts
@@ -1,7 +1,12 @@
 import { createLogger } from '@sim/logger'
 import { type NextRequest, NextResponse } from 'next/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
-import { validateAlphanumericId, validateJiraCloudId } from '@/lib/core/security/input-validation'
+import {
+  validateAlphanumericId,
+  validateJiraCloudId,
+  validateNumericId,
+  validatePaginationCursor,
+} from '@/lib/core/security/input-validation'
 import { cleanHtmlContent, getConfluenceCloudId } from '@/tools/confluence/utils'
 
 const logger = createLogger('ConfluencePageVersionsAPI')
@@ -57,8 +62,14 @@ export async function POST(request: NextRequest) {
 
     // If versionNumber is provided, get specific version with page content
     if (versionNumber !== undefined && versionNumber !== null) {
-      const versionUrl = `https://api.atlassian.com/ex/confluence/${cloudId}/wiki/api/v2/pages/${pageId}/versions/${versionNumber}`
-      const pageUrl = `https://api.atlassian.com/ex/confluence/${cloudId}/wiki/api/v2/pages/${pageId}?version=${versionNumber}&body-format=storage`
+      const versionValidation = validateNumericId(versionNumber, 'versionNumber', { min: 1 })
+      if (!versionValidation.isValid) {
+        return NextResponse.json({ error: versionValidation.error }, { status: 400 })
+      }
+      const safeVersion = versionValidation.sanitized
+
+      const versionUrl = `https://api.atlassian.com/ex/confluence/${cloudId}/wiki/api/v2/pages/${pageId}/versions/${safeVersion}`
+      const pageUrl = `https://api.atlassian.com/ex/confluence/${cloudId}/wiki/api/v2/pages/${pageId}?version=${safeVersion}&body-format=storage`
 
       logger.info(`Fetching version ${versionNumber} for page ${pageId}`)
 
@@ -135,6 +146,10 @@ export async function POST(request: NextRequest) {
     queryParams.append('limit', String(Math.min(limit, 250)))
 
     if (cursor) {
+      const cursorValidation = validatePaginationCursor(cursor, 'cursor')
+      if (!cursorValidation.isValid) {
+        return NextResponse.json({ error: cursorValidation.error }, { status: 400 })
+      }
       queryParams.append('cursor', cursor)
     }
 
diff --git a/apps/sim/app/api/tools/confluence/space-permissions/route.ts b/apps/sim/app/api/tools/confluence/space-permissions/route.ts
index c1a063e2cf..8a046a0f6c 100644
--- a/apps/sim/app/api/tools/confluence/space-permissions/route.ts
+++ b/apps/sim/app/api/tools/confluence/space-permissions/route.ts
@@ -1,7 +1,11 @@
 import { createLogger } from '@sim/logger'
 import { type NextRequest, NextResponse } from 'next/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
-import { validateAlphanumericId, validateJiraCloudId } from '@/lib/core/security/input-validation'
+import {
+  validateAlphanumericId,
+  validateJiraCloudId,
+  validatePaginationCursor,
+} from '@/lib/core/security/input-validation'
 import { getConfluenceCloudId } from '@/tools/confluence/utils'
 
 const logger = createLogger('ConfluenceSpacePermissionsAPI')
@@ -50,6 +54,10 @@ export async function POST(request: NextRequest) {
     queryParams.append('limit', String(Math.min(limit, 250)))
 
     if (cursor) {
+      const cursorValidation = validatePaginationCursor(cursor, 'cursor')
+      if (!cursorValidation.isValid) {
+        return NextResponse.json({ error: cursorValidation.error }, { status: 400 })
+      }
       queryParams.append('cursor', cursor)
     }
 
diff --git a/apps/sim/app/api/tools/confluence/space-properties/route.ts b/apps/sim/app/api/tools/confluence/space-properties/route.ts
index dce10a74cb..5bdd176aff 100644
--- a/apps/sim/app/api/tools/confluence/space-properties/route.ts
+++ b/apps/sim/app/api/tools/confluence/space-properties/route.ts
@@ -1,7 +1,11 @@
 import { createLogger } from '@sim/logger'
 import { type NextRequest, NextResponse } from 'next/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
-import { validateAlphanumericId, validateJiraCloudId } from '@/lib/core/security/input-validation'
+import {
+  validateAlphanumericId,
+  validateJiraCloudId,
+  validatePaginationCursor,
+} from '@/lib/core/security/input-validation'
 import { getConfluenceCloudId } from '@/tools/confluence/utils'
 
 const logger = createLogger('ConfluenceSpacePropertiesAPI')
@@ -82,7 +86,7 @@ export async function POST(request: NextRequest) {
         return NextResponse.json({ error: propertyIdValidation.error }, { status: 400 })
       }
 
-      const url = `${baseUrl}/${propertyId}`
+      const url = `${baseUrl}/${encodeURIComponent(propertyId)}`
 
       logger.info(`Deleting space property ${propertyId} from space ${spaceId}`)
 
@@ -148,7 +152,13 @@ export async function POST(request: NextRequest) {
     const queryParams = new URLSearchParams()
     queryParams.append('limit', String(Math.min(limit, 250)))
 
-    if (cursor) queryParams.append('cursor', cursor)
+    if (cursor) {
+      const cursorValidation = validatePaginationCursor(cursor, 'cursor')
+      if (!cursorValidation.isValid) {
+        return NextResponse.json({ error: cursorValidation.error }, { status: 400 })
+      }
+      queryParams.append('cursor', cursor)
+    }
 
     const url = `${baseUrl}?${queryParams.toString()}`
 
diff --git a/apps/sim/app/api/tools/confluence/tasks/route.ts b/apps/sim/app/api/tools/confluence/tasks/route.ts
index 46031dcc4f..e74ca3b540 100644
--- a/apps/sim/app/api/tools/confluence/tasks/route.ts
+++ b/apps/sim/app/api/tools/confluence/tasks/route.ts
@@ -1,7 +1,12 @@
 import { createLogger } from '@sim/logger'
 import { type NextRequest, NextResponse } from 'next/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
-import { validateAlphanumericId, validateJiraCloudId } from '@/lib/core/security/input-validation'
+import {
+  validateAlphanumericId,
+  validateJiraCloudId,
+  validatePaginationCursor,
+  validatePathSegment,
+} from '@/lib/core/security/input-validation'
 import { getConfluenceCloudId } from '@/tools/confluence/utils'
 
 const logger = createLogger('ConfluenceTasksAPI')
@@ -180,11 +185,40 @@ export async function POST(request: NextRequest) {
     const queryParams = new URLSearchParams()
     queryParams.append('limit', String(Math.min(limit, 250)))
 
-    if (cursor) queryParams.append('cursor', cursor)
+    if (cursor) {
+      const cursorValidation = validatePaginationCursor(cursor, 'cursor')
+      if (!cursorValidation.isValid) {
+        return NextResponse.json({ error: cursorValidation.error }, { status: 400 })
+      }
+      queryParams.append('cursor', cursor)
+    }
     if (taskStatus) queryParams.append('status', taskStatus)
-    if (pageId) queryParams.append('page-id', pageId)
-    if (spaceId) queryParams.append('space-id', spaceId)
-    if (assignedTo) queryParams.append('assigned-to', assignedTo)
+    if (pageId) {
+      const pageIdValidation = validateAlphanumericId(pageId, 'pageId', 255)
+      if (!pageIdValidation.isValid) {
+        return NextResponse.json({ error: pageIdValidation.error }, { status: 400 })
+      }
+      queryParams.append('page-id', pageId)
+    }
+    if (spaceId) {
+      const spaceIdValidation = validateAlphanumericId(spaceId, 'spaceId', 255)
+      if (!spaceIdValidation.isValid) {
+        return NextResponse.json({ error: spaceIdValidation.error }, { status: 400 })
+      }
+      queryParams.append('space-id', spaceId)
+    }
+    if (assignedTo) {
+      // Atlassian account IDs: 5d5bd05c3aee0123abc or 557058:6b9c9931-4693-49c1-8b3a-931f1af98134
+      const assignedToValidation = validatePathSegment(assignedTo, {
+        paramName: 'assignedTo',
+        maxLength: 128,
+        customPattern: /^[a-zA-Z0-9_|:-]+$/,
+      })
+      if (!assignedToValidation.isValid) {
+        return NextResponse.json({ error: assignedToValidation.error }, { status: 400 })
+      }
+      queryParams.append('assigned-to', assignedTo)
+    }
 
     const url = `https://api.atlassian.com/ex/confluence/${cloudId}/wiki/api/v2/tasks?${queryParams.toString()}`
 
diff --git a/apps/sim/app/api/tools/confluence/user/route.ts b/apps/sim/app/api/tools/confluence/user/route.ts
index 68ea52bd1d..5b81116d80 100644
--- a/apps/sim/app/api/tools/confluence/user/route.ts
+++ b/apps/sim/app/api/tools/confluence/user/route.ts
@@ -34,11 +34,11 @@ export async function POST(request: NextRequest) {
       return NextResponse.json({ error: 'Account ID is required' }, { status: 400 })
     }
 
-    // Atlassian account IDs use format like 557058:6b9c9931-4693-49c1-8b3a-931f1af98134
+    // Atlassian account IDs: 5d5bd05c3aee0123abc or 557058:6b9c9931-4693-49c1-8b3a-931f1af98134
     const accountIdValidation = validatePathSegment(accountId, {
       paramName: 'accountId',
-      maxLength: 255,
-      customPattern: /^[a-zA-Z0-9:-]+$/,
+      maxLength: 128,
+      customPattern: /^[a-zA-Z0-9_|:-]+$/,
     })
     if (!accountIdValidation.isValid) {
       return NextResponse.json({ error: accountIdValidation.error }, { status: 400 })
diff --git a/apps/sim/lib/core/security/input-validation.ts b/apps/sim/lib/core/security/input-validation.ts
index 06bc41b069..cd005277ba 100644
--- a/apps/sim/lib/core/security/input-validation.ts
+++ b/apps/sim/lib/core/security/input-validation.ts
@@ -1039,3 +1039,74 @@ export function validateGoogleCalendarId(
 
   return { isValid: true, sanitized: value }
 }
+
+/**
+ * Validates a pagination cursor token
+ *
+ * Pagination cursors are opaque tokens returned by APIs (e.g., Confluence, Jira)
+ * and passed back to get the next page. They are typically base64-encoded or
+ * URL-safe strings. This validator ensures the cursor cannot contain characters
+ * that could alter URL structure.
+ *
+ * @param value - The cursor token to validate
+ * @param paramName - Name of the parameter for error messages
+ * @param maxLength - Maximum length (default: 1024)
+ * @returns ValidationResult
+ *
+ * @example
+ * ```typescript
+ * if (cursor) {
+ *   const result = validatePaginationCursor(cursor, 'cursor')
+ *   if (!result.isValid) {
+ *     return NextResponse.json({ error: result.error }, { status: 400 })
+ *   }
+ * }
+ * ```
+ */
+export function validatePaginationCursor(
+  value: string | null | undefined,
+  paramName = 'cursor',
+  maxLength = 1024
+): ValidationResult {
+  if (value === null || value === undefined || value === '') {
+    return {
+      isValid: false,
+      error: `${paramName} is required`,
+    }
+  }
+
+  if (value.length > maxLength) {
+    logger.warn('Pagination cursor exceeds maximum length', {
+      paramName,
+      length: value.length,
+      maxLength,
+    })
+    return {
+      isValid: false,
+      error: `${paramName} exceeds maximum length of ${maxLength} characters`,
+    }
+  }
+
+  if (/[\x00-\x1f\x7f]/.test(value) || value.includes('%00')) {
+    logger.warn('Pagination cursor contains control characters', { paramName })
+    return {
+      isValid: false,
+      error: `${paramName} contains invalid characters`,
+    }
+  }
+
+  // Allow alphanumeric, base64 chars (+, /, =), and URL-safe chars (-, _, ., ~, %)
+  const cursorPattern = /^[A-Za-z0-9+/=\-_.~%]+$/
+  if (!cursorPattern.test(value)) {
+    logger.warn('Pagination cursor contains disallowed characters', {
+      paramName,
+      value: value.substring(0, 100),
+    })
+    return {
+      isValid: false,
+      error: `${paramName} contains invalid characters`,
+    }
+  }
+
+  return { isValid: true, sanitized: value }
+}