CVE-2026-42554— Fiber: XSS in AutoFormat Content Negotiation
Possible ATT&CK Techniques 2AI
T1059 · Command and Scripting Interpreter T1189 · Drive-by CompromiseGet alerts for future matching vulnerabilitiesLog in to subscribe
I. Basic Information for CVE-2026-42554
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗ Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Fiber: XSS in AutoFormat Content Negotiation
Source: NVD (National Vulnerability Database)
Vulnerability Description
Fiber is a web framework for Go. Prior to 2.52.12 and 3.1.0, Cross-Site Scripting vulnerability in Go Fiber allows a remote attacker to inject arbitrary HTML/JavaScript by supplying Accept: text/html on any request whose handler passes attacker-influenced data to the AutoFormat() feature. The developer opts into content negotiation by calling AutoFormat(), but does not opt into raw HTML emission for a particular request; Fiber chooses that branch from attacker-controlled Accept. The html branch is the sole outlier in a method whose name (AutoFormat) and symmetrical structure actively telegraph "safe, format-agnostic reply." This vulnerability is fixed in 2.52.12 and 3.1.0.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
在Web页面生成时对输入的转义处理不恰当(跨站脚本)
Source: NVD (National Vulnerability Database)
Vulnerability Title
Fiber 跨站脚本漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Fiber是Fiber开源的一款使用Go语言编写的开源Web框架。 Fiber 2.52.12之前版本和3.1.0之前版本存在跨站脚本漏洞，该漏洞源于跨站脚本，可能导致远程攻击者通过提供Accept: text/html在任意请求中注入任意HTML/JavaScript，当处理程序将攻击者影响的数据传递给AutoFormat()功能时触发。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2026-42554
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POCPremium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-42554
请登录查看更多情报信息。
- https://github.com/gofiber/fiber/security/advisories/GHSA-qjv7-627w-8qjvx_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2026-42554
IV. Related Vulnerabilities
Same product: fiber
- CVE-2026-30246
github.com/gofiber/fiber/v3 cache middleware can mix respons - CVE-2026-25899
Fiber is Vulnerable to Denial of Service via Flash Cookie Un - CVE-2026-25891
Fiber has an Arbitrary File Read in Static Middleware on Win - CVE-2026-25882
Fiber has a Denial of Service Vulnerability via Route Parame - CVE-2025-66630
Fiber insecurely fallsback in utils.UUIDv4() / utils.UUID()
Same vendor: gofiber
- CVE-2026-30246
github.com/gofiber/fiber/v3 cache middleware can mix respons - CVE-2026-25899
Fiber is Vulnerable to Denial of Service via Flash Cookie Un - CVE-2026-25891
Fiber has an Arbitrary File Read in Static Middleware on Win - CVE-2026-25882
Fiber has a Denial of Service Vulnerability via Route Parame - CVE-2025-66630
Fiber insecurely fallsback in utils.UUIDv4() / utils.UUID()
Same weakness: CWE-79
- CVE-2026-27737
BigBlueButton has Stored XSS in bbb-playback replay - CVE-2026-45231
DumbAssets 1.0.11 Stored Cross-Site Scripting via Asset Fiel - CVE-2026-45494
Microsoft Edge (Chromium-based) Spoofing Vulnerability - CVE-2026-7498
Stored XSS in Basamak Informatics' DernekWeb - CVE-2026-3495
Unescaped variables during error page composition
V. Comments for CVE-2026-42554
No comments yet