Category

Denial Of Service

Security vulnerabilities and automated fixes for denial of service issues

25 posts found

high5 min

How Memory Exhaustion via Large Comma-Separated Selector Lists happens in Python Soup Sieve and how to fix it

A high-severity memory exhaustion vulnerability (CVE-2026-49476) was discovered in Soup Sieve version 2.8.3, affecting Python applications that parse CSS selectors from user-controlled input. The vulnerability allows attackers to craft malicious selector lists that consume excessive memory, potentially causing denial of service. The fix involves upgrading to soupsieve 2.8.4, which implements proper resource limits on selector parsing.

#security#python#denial-of-service+4 more
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orbisai0security
Jul 12, 2026
high5 min

How memory exhaustion via large comma-separated selector lists happens in Python soupsieve and how to fix it

A high-severity memory exhaustion vulnerability (CVE-2026-49476) was discovered in soupsieve 2.8.3, a CSS selector library used by BeautifulSoup in Python. An attacker who could influence CSS selector input could craft large comma-separated selector lists to exhaust system memory, causing denial of service. The fix upgrades soupsieve from 2.8.3 to 2.8.4 in the backend's `uv.lock` dependency file.

#security#python#denial-of-service+4 more
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orbisai0security
Jul 11, 2026
high8 min

How SSH channel exhaustion happens in Go crypto and how to fix it

CVE-2026-39827 is a high-severity resource exhaustion vulnerability in `golang.org/x/crypto` where an authenticated SSH client can repeatedly open channels to consume server resources without bound. The vulnerability was present in the `cloud/gcp/functions/acmedns` module at version `v0.49.0` and was resolved by upgrading to `v0.52.0`. Left unpatched, this flaw could allow an attacker with valid SSH credentials to degrade or deny service to other users of the affected GCP Cloud Function.

#golang#ssh#cve-2026-39827+4 more
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orbisai0security
Jul 11, 2026
high9 min

How Regular Expression Denial of Service happens in Node.js picomatch extglob patterns and how to fix it

A Regular Expression Denial of Service (ReDoS) vulnerability in picomatch versions prior to 2.3.2, 3.0.2, and 4.0.4 allowed attackers to craft malicious extglob patterns that triggered catastrophic backtracking in the regex engine, potentially freezing Node.js applications. The fix, tracked as CVE-2026-33671, involved upgrading picomatch to patched versions and pinning the dependency explicitly in `package.json` to ensure the safe version is resolved across the dependency tree.

#nodejs#regex#redos+4 more
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orbisai0security
Jul 9, 2026
high8 min

How Denial of Service happens in Node.js devalue and how to fix it

A high-severity Denial of Service vulnerability (CVE-2026-22774) was discovered in the `devalue` package used by the exo-dashboard SvelteKit application. Attackers could craft malicious input to trigger excessive resource consumption in the devalue deserialization library, potentially taking down the web service. The fix upgrades `devalue` from version 5.5.0 to 5.6.2 in both `package.json` and `package-lock.json`.

#denial-of-service#nodejs#sveltekit+4 more
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orbisai0security
Jun 25, 2026
high6 min

How unbounded input size denial-of-service happens in C lexer functions and how to fix it

A high-severity denial-of-service vulnerability was discovered in the PH7 lexer where the `PH7_TokenizePHP()` function accepted arbitrarily large input sizes without validation. An attacker could submit gigabyte-scale PHP code, causing proportional CPU and memory exhaustion. The fix introduces a configurable input size cap enforced before lexer processing begins.

#security#denial-of-service#c-programming+4 more
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orbisai0security
Jun 23, 2026
high7 min

How form limit bypass DoS happens in Python Starlette and how to fix it

CVE-2026-54283 is a high-severity denial-of-service vulnerability in Starlette where size limits set on `request.form()` were silently ignored for `application/x-www-form-urlencoded` content, allowing attackers to submit unbounded form data and exhaust server resources. The fix upgrades Starlette from version 1.2.1 to 1.3.1, which correctly enforces form size limits for all content types. Any Python web application using Starlette (including FastAPI-based services) that accepts form submissions

#python#starlette#fastapi+4 more
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orbisai0security
Jun 22, 2026
high6 min

How Denial of Service via crafted URI templates happens in Ruby addressable and how to fix it

A high-severity Denial of Service vulnerability (CVE-2026-35611) was discovered in the Ruby `addressable` gem versions prior to 2.9.0, which could allow attackers to crash or hang applications by sending specially crafted URI templates. The fix upgrades the dependency from version 2.8.7 to 2.9.0 across the Gemfile, Gemfile.lock, and gemspec in a Fastlane project, eliminating the vulnerable code path entirely.

#security#ruby#denial-of-service+4 more
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orbisai0security
Jun 12, 2026
high5 min

How Denial of Service in SSH Key Exchange happens in Go golang.org/x/crypto and how to fix it

A high-severity denial of service vulnerability (CVE-2025-22869) was discovered in the SSH key exchange implementation of Go's `golang.org/x/crypto` library. The `cpdaemon` service depended on the vulnerable version v0.32.0, which could allow an attacker to exhaust server resources during the SSH handshake phase. The fix upgrades the dependency to v0.35.0, which includes the upstream patch for this vulnerability.

#security#go#golang+4 more
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orbisai0security
Jun 10, 2026
high7 min

How DoS via sparse array deserialization happens in Svelte devalue and how to fix it

A high-severity vulnerability (CVE-2026-42570) was discovered in the devalue library version 5.7.1, used by the Astro-powered website. This vulnerability allowed attackers to trigger denial-of-service conditions through maliciously crafted sparse arrays during deserialization. The fix involved upgrading devalue from 5.7.1 to 5.8.1, which implements proper safeguards against sparse array exploitation.

#security#denial-of-service#javascript+4 more
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orbisai0security
Jun 9, 2026
high6 min

NULL Pointer Dereference in ESP8266 user_interface.c wifi_station_set_default_hostname()

A critical NULL pointer dereference vulnerability in the ESP8266 firmware's `user_interface.c` allowed attackers to crash devices by exhausting the limited 80KB heap memory. The `wifi_station_set_default_hostname()` function's `os_malloc` call lacked a proper NULL guard, causing `ets_sprintf` to write to address 0 when allocation failed. The fix corrected a logic inversion in the NULL check condition.

#security#null-pointer-dereference#esp8266+4 more
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orbisai0security
Jun 3, 2026
high7 min

DoS via Sparse Array Deserialization in devalue: CVE-2026-42570 Fixed

A high-severity Denial of Service vulnerability (CVE-2026-42570) was discovered in the `devalue` library used by the Orbis AppSec blog site, where maliciously crafted sparse arrays during deserialization could exhaust server resources. The fix upgrades `devalue` from version 5.6.4 to 5.8.1 in `blog-site/package-lock.json` and adds an explicit override in `package.json` to ensure the patched version is consistently enforced across the dependency tree. Left unpatched, this vulnerability could have

#cve-2026-42570#denial-of-service#devalue+4 more
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orbisai0security
Jun 1, 2026