Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation

Summary DRF's content negotiation parses each Accept token several times per request and never limits the number of tokens or their total size. Each parse ends up in Django's parseheaderparameters, which takes quadratic time when a quoted parameter value is packed with semicolons. On my machine a...

CVE-2026-114138 Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation

Django REST framework is a toolkit for building Web APIs. Prior to 3.18.2, DefaultContentNegotiation.getacceptlist in restframework/negotiation.py accepts an unbounded number and aggregate size of Accept tokens, while selectrenderer in that file repeatedly invokes MediaType parsing from...

CVE-2026-114138

The Django REST framework toolkit is vulnerable to a denial of service (DoS) attack due to inefficient algorithmic complexity in content negotiation. Specifically, the DefaultContentNegotiation.get_accept_list function in rest_framework/negotiation.py accepts an unbounded number and size of Accep...

CVE-2026-114138 Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation

Django REST framework is a toolkit for building Web APIs. Prior to 3.18.2, DefaultContentNegotiation.getacceptlist in restframework/negotiation.py accepts an unbounded number and aggregate size of Accept tokens, while selectrenderer in that file repeatedly invokes MediaType parsing from...

SUSE CVE-2026-42554

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...

CVE-2026-66062

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

GHSA-29G2-3RMR-QM68 SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header

Impact SvelteKit is vulnerable to remote CPU-exhaustion DoS attacks via specifically-crafted Accept headers. The impact is mitigated by default header length limits on most platforms, but in the case of raised or absent limits a denial of service is possible. Patches The vulnerability is patched ...

SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header

Impact SvelteKit is vulnerable to remote CPU-exhaustion DoS attacks via specifically-crafted Accept headers. The impact is mitigated by default header length limits on most platforms, but in the case of raised or absent limits a denial of service is possible. Patches The vulnerability is patched ...

CVE-2026-66062

SvelteKit before 2.70.2 uses a content-negotiation header parser that employs a regular expression vulnerable to quadratic backtracking. A crafted Accept header can cause excessive CPU use, leading to degraded performance or denial of service. The issue is fixed in 2.70.2. No exploitation details...

CVE-2026-66062 SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

CVE-2026-66062 SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

CVE-2026-66062

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

EUVD-2026-54557

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

CVE-2026-66062 SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

CVE-2026-66062: Inefficient Regular Expression Complexity

SvelteKit is a framework for rapidly developing robust, performant web applications using Svelte. Prior to 2.70.2, the content negotiation header parser used by SvelteKit's request handling for headers such as Accept uses a regular expression vulnerable to quadratic backtracking, so a maliciously...

GO-2026-5585 Fiber vulnerable to XSS in AutoFormat Content Negotiation in github.com/gofiber/fiber

Fiber vulnerable to XSS in AutoFormat Content Negotiation in github.com/gofiber/fiber...

CVE-2026-42554 Fiber: XSS in AutoFormat Content Negotiation

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...

CVE-2026-42554 Fiber: XSS in AutoFormat Content Negotiation

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...

CVE-2026-42554 Fiber: XSS in AutoFormat Content Negotiation

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...

CVE-2026-42554

CVE-2026-42554 describes an XSS in Fiber’s AutoFormat content negotiation. Affected: GoFiber/v3 up to 3.1.0 and GoFiber/v2 up to 2.52.12. Root cause: the html branch of AutoFormat can emit raw, attacker-influenced data wrapped in HTML when the client sends Accept: text/html, enabling injection of...