diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts b/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts
index 07d70365d6..6252e7e929 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/list-remote.ts
@@ -2,6 +2,7 @@ import define from "../../../define.js";
 import { Emojis } from "@/models/index.js";
 import { toPuny } from "@/misc/convert-host.js";
 import { makePaginationQuery } from "../../../common/make-pagination-query.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["admin"],
@@ -106,7 +107,9 @@ export default define(meta, paramDef, async (ps) => {
 	}
 
 	if (ps.query) {
-		q.andWhere("emoji.name like :query", { query: `%${ps.query}%` });
+		q.andWhere("emoji.name like :query", {
+			query: `%${sqlLikeEscape(ps.query)}%`,
+		});
 	}
 
 	const emojis = await q.orderBy("emoji.id", "DESC").take(ps.limit).getMany();
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/list.ts b/packages/backend/src/server/api/endpoints/admin/emoji/list.ts
index 9390dfb202..f8269588ca 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/list.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/list.ts
@@ -2,6 +2,7 @@ import define from "../../../define.js";
 import { Emojis } from "@/models/index.js";
 import { makePaginationQuery } from "../../../common/make-pagination-query.js";
 import type { Emoji } from "@/models/entities/emoji.js";
+//import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["admin"],
@@ -96,7 +97,7 @@ export default define(meta, paramDef, async (ps) => {
 	let emojis: Emoji[];
 
 	if (ps.query) {
-		//q.andWhere('emoji.name ILIKE :q', { q: `%${ps.query}%` });
+		//q.andWhere('emoji.name ILIKE :q', { q: `%${sqlLikeEscape(ps.query)}%` });
 		//const emojis = await q.take(ps.limit).getMany();
 
 		emojis = await q.getMany();
diff --git a/packages/backend/src/server/api/endpoints/admin/show-users.ts b/packages/backend/src/server/api/endpoints/admin/show-users.ts
index 868df9dc9b..b777bd26d9 100644
--- a/packages/backend/src/server/api/endpoints/admin/show-users.ts
+++ b/packages/backend/src/server/api/endpoints/admin/show-users.ts
@@ -1,5 +1,6 @@
 import { Users } from "@/models/index.js";
 import define from "../../define.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["admin"],
@@ -106,7 +107,7 @@ export default define(meta, paramDef, async (ps, me) => {
 
 	if (ps.username) {
 		query.andWhere("user.usernameLower like :username", {
-			username: `${ps.username.toLowerCase()}%`,
+			username: `${sqlLikeEscape(ps.username.toLowerCase())}%`,
 		});
 	}
 
diff --git a/packages/backend/src/server/api/endpoints/federation/instances.ts b/packages/backend/src/server/api/endpoints/federation/instances.ts
index 646f38282b..fa1a415312 100644
--- a/packages/backend/src/server/api/endpoints/federation/instances.ts
+++ b/packages/backend/src/server/api/endpoints/federation/instances.ts
@@ -2,6 +2,7 @@ import config from "@/config/index.js";
 import define from "../../define.js";
 import { Instances } from "@/models/index.js";
 import { fetchMeta } from "@/misc/fetch-meta.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["federation"],
@@ -178,7 +179,7 @@ export default define(meta, paramDef, async (ps, me) => {
 
 	if (ps.host) {
 		query.andWhere("instance.host like :host", {
-			host: `%${ps.host.toLowerCase()}%`,
+			host: `%${sqlLikeEscape(ps.host.toLowerCase())}%`,
 		});
 	}
 
diff --git a/packages/backend/src/server/api/endpoints/hashtags/search.ts b/packages/backend/src/server/api/endpoints/hashtags/search.ts
index 95bc608ece..cde586af0c 100644
--- a/packages/backend/src/server/api/endpoints/hashtags/search.ts
+++ b/packages/backend/src/server/api/endpoints/hashtags/search.ts
@@ -1,5 +1,6 @@
 import define from "../../define.js";
 import { Hashtags } from "@/models/index.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["hashtags"],
@@ -31,7 +32,9 @@ export const paramDef = {
 
 export default define(meta, paramDef, async (ps) => {
 	const hashtags = await Hashtags.createQueryBuilder("tag")
-		.where("tag.name like :q", { q: `${ps.query.toLowerCase()}%` })
+		.where("tag.name like :q", {
+			q: `${sqlLikeEscape(ps.query.toLowerCase())}%`,
+		})
 		.orderBy("tag.count", "DESC")
 		.groupBy("tag.id")
 		.take(ps.limit)
diff --git a/packages/backend/src/server/api/endpoints/notes/search.ts b/packages/backend/src/server/api/endpoints/notes/search.ts
index 8f563c384f..93392acddf 100644
--- a/packages/backend/src/server/api/endpoints/notes/search.ts
+++ b/packages/backend/src/server/api/endpoints/notes/search.ts
@@ -9,6 +9,7 @@ import { makePaginationQuery } from "../../common/make-pagination-query.js";
 import { generateVisibilityQuery } from "../../common/generate-visibility-query.js";
 import { generateMutedUserQuery } from "../../common/generate-muted-user-query.js";
 import { generateBlockedUserQuery } from "../../common/generate-block-query.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["notes"],
@@ -77,7 +78,7 @@ export default define(meta, paramDef, async (ps, me) => {
 		}
 
 		query
-			.andWhere("note.text ILIKE :q", { q: `%${ps.query}%` })
+			.andWhere("note.text ILIKE :q", { q: `%${sqlLikeEscape(ps.query)}%` })
 			.innerJoinAndSelect("note.user", "user")
 			.leftJoinAndSelect("user.avatar", "avatar")
 			.leftJoinAndSelect("user.banner", "banner")
diff --git a/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts b/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
index 99aa2f1af3..eeccf69386 100644
--- a/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
+++ b/packages/backend/src/server/api/endpoints/users/search-by-username-and-host.ts
@@ -3,6 +3,7 @@ import { Followings, Users } from "@/models/index.js";
 import { USER_ACTIVE_THRESHOLD } from "@/const.js";
 import type { User } from "@/models/entities/user.js";
 import define from "../../define.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["users"],
@@ -44,11 +45,13 @@ export default define(meta, paramDef, async (ps, me) => {
 	if (ps.host) {
 		const q = Users.createQueryBuilder("user")
 			.where("user.isSuspended = FALSE")
-			.andWhere("user.host LIKE :host", { host: `${ps.host.toLowerCase()}%` });
+			.andWhere("user.host LIKE :host", {
+				host: `${sqlLikeEscape(ps.host.toLowerCase())}%`,
+			});
 
 		if (ps.username) {
 			q.andWhere("user.usernameLower LIKE :username", {
-				username: `${ps.username.toLowerCase()}%`,
+				username: `${sqlLikeEscape(ps.username.toLowerCase())}%`,
 			});
 		}
 
@@ -71,7 +74,7 @@ export default define(meta, paramDef, async (ps, me) => {
 				.andWhere("user.id != :meId", { meId: me.id })
 				.andWhere("user.isSuspended = FALSE")
 				.andWhere("user.usernameLower LIKE :username", {
-					username: `${ps.username.toLowerCase()}%`,
+					username: `${sqlLikeEscape(ps.username.toLowerCase())}%`,
 				})
 				.andWhere(
 					new Brackets((qb) => {
@@ -95,7 +98,7 @@ export default define(meta, paramDef, async (ps, me) => {
 					.andWhere("user.id != :meId", { meId: me.id })
 					.andWhere("user.isSuspended = FALSE")
 					.andWhere("user.usernameLower LIKE :username", {
-						username: `${ps.username.toLowerCase()}%`,
+						username: `${sqlLikeEscape(ps.username.toLowerCase())}%`,
 					})
 					.andWhere("user.updatedAt IS NOT NULL");
 
@@ -112,7 +115,7 @@ export default define(meta, paramDef, async (ps, me) => {
 			users = await Users.createQueryBuilder("user")
 				.where("user.isSuspended = FALSE")
 				.andWhere("user.usernameLower LIKE :username", {
-					username: `${ps.username.toLowerCase()}%`,
+					username: `${sqlLikeEscape(ps.username.toLowerCase())}%`,
 				})
 				.andWhere("user.updatedAt IS NOT NULL")
 				.orderBy("user.updatedAt", "DESC")
diff --git a/packages/backend/src/server/api/endpoints/users/search.ts b/packages/backend/src/server/api/endpoints/users/search.ts
index db687a1075..2d84d5bfeb 100644
--- a/packages/backend/src/server/api/endpoints/users/search.ts
+++ b/packages/backend/src/server/api/endpoints/users/search.ts
@@ -2,6 +2,7 @@ import { Brackets } from "typeorm";
 import { UserProfiles, Users } from "@/models/index.js";
 import type { User } from "@/models/entities/user.js";
 import define from "../../define.js";
+import { sqlLikeEscape } from "@/misc/sql-like-escape.js";
 
 export const meta = {
 	tags: ["users"],
@@ -50,7 +51,7 @@ export default define(meta, paramDef, async (ps, me) => {
 	if (isUsername) {
 		const usernameQuery = Users.createQueryBuilder("user")
 			.where("user.usernameLower LIKE :username", {
-				username: `${ps.query.replace("@", "").toLowerCase()}%`,
+				username: `${sqlLikeEscape(ps.query.replace("@", "").toLowerCase())}%`,
 			})
 			.andWhere(
 				new Brackets((qb) => {
@@ -77,12 +78,14 @@ export default define(meta, paramDef, async (ps, me) => {
 		const nameQuery = Users.createQueryBuilder("user")
 			.where(
 				new Brackets((qb) => {
-					qb.where("user.name ILIKE :query", { query: `%${ps.query}%` });
+					qb.where("user.name ILIKE :query", {
+						query: `%${sqlLikeEscape(ps.query)}%`,
+					});
 
 					// Also search username if it qualifies as username
 					if (Users.validateLocalUsername(ps.query)) {
 						qb.orWhere("user.usernameLower LIKE :username", {
-							username: `%${ps.query.toLowerCase()}%`,
+							username: `%${sqlLikeEscape(ps.query.toLowerCase())}%`,
 						});
 					}
 				}),
@@ -113,7 +116,7 @@ export default define(meta, paramDef, async (ps, me) => {
 			const profQuery = UserProfiles.createQueryBuilder("prof")
 				.select("prof.userId")
 				.where("prof.description ILIKE :query", {
-					query: `%${ps.query}%`,
+					query: `%${sqlLikeEscape(ps.query)}%`,
 				});
 
 			if (ps.origin === "local") {