CVE-2026-48076

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. The new-client booking flow in versions 1.0.1 and prior consists of three calls: bootstrap-challenge returns a 16-bit PoW challenge with difficulty=4 leading hex zeroes, bootstrap-verify...

CVE-2026-48082

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.6, the bootstrap challenge endpoint at /api/tenants/id/appointments/bootstrap-challenge issues a SHA-256 proof-of-work with difficulty=4 hex zeros, equivalent to 16 bit...

CVE-2026-48082 OpenReception's bootstrap challenge proof-of-work difficulty hardcoded to 16 bits, which enables abuse rate amplification

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.6, the bootstrap challenge endpoint at /api/tenants/id/appointments/bootstrap-challenge issues a SHA-256 proof-of-work with difficulty=4 hex zeros, equivalent to 16 bit...

CVE-2026-48082 OpenReception's bootstrap challenge proof-of-work difficulty hardcoded to 16 bits, which enables abuse rate amplification

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.6, the bootstrap challenge endpoint at /api/tenants/id/appointments/bootstrap-challenge issues a SHA-256 proof-of-work with difficulty=4 hex zeros, equivalent to 16 bit...

CVE-2026-48082

OpenReception’s OpenReception appointment-booking software before v1.0.6 uses a bootstrap-challenge PoW endpoint (/api/tenants/{id}/appointments/bootstrap-challenge) that requires SHA-256 with difficulty=4 hex zeros (≈16 bits). Modern hardware solves this quickly, undermining rate-limiting for un...

CVE-2026-48076 OpenReception's bootstrap booking flow allows unauthenticated booking on isPublic=false channels

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. The new-client booking flow in versions 1.0.1 and prior consists of three calls: bootstrap-challenge returns a 16-bit PoW challenge with difficulty=4 leading hex zeroes, bootstrap-verify...

[SECURITY] Fedora 44 Update: nginx-mod-js-challenge-0^20230517.gitda6852d-11.fc44

Simple JavaScript proof-of-work based access for Nginx with virtually no over head...

PYSEC-2026-1115 ALTCHA Proof-of-Work Vulnerable to Challenge Splicing and Replay

Impact A cryptographic semantic binding flaw in ALTCHA libraries allows challenge payload splicing, which may enable replay attacks. The HMAC signature does not unambiguously bind challenge parameters to the nonce, allowing an attacker to reinterpret a valid proof-of-work submission with a modifi...

[SECURITY] Fedora 44 Update: nginx-mod-js-challenge-0^20230517.gitda6852d-9.fc44

Simple JavaScript proof-of-work based access for Nginx with virtually no over head...

[SECURITY] Fedora 44 Update: nginx-mod-js-challenge-0^20230517.gitda6852d-8.fc44

Simple JavaScript proof-of-work based access for Nginx with virtually no over head...

[SECURITY] Fedora 44 Update: nginx-mod-js-challenge-0^20230517.gitda6852d-7.fc44

Simple JavaScript proof-of-work based access for Nginx with virtually no over head...

cap-exploit-poc

cap-exploit-poc This repository contai...

SDN-SYN PoW: Intent-Aware Adaptive SDN Defense with PoW against Multi-Domain SYN Floods

The stability of Internet services is persistently challenged by the escalating scale of volumetric TCP SYN floods, as conventional defenses like SYN Cookies fail by exacerbating bandwidth depletion under modern attacks. This paper introduces SDN-SYN PoW, a novel defense architecture that...

NGCaptcha: A CAPTCHA Bridging the past and the Future

CAPTCHAs are widely employed for distinguishing humans from automated bots online. However, current vision based CAPTCHAs face escalating security risks: traditional attacks continue to bypass many deployed CAPTCHA schemes, and recent breakthroughs in AI, particularly large scale vision models,...

GO-2025-4239 ALTCHA Proof-of-Work Vulnerable to Challenge Splicing and Replay in github.com/altcha-org/altcha-lib-go

ALTCHA Proof-of-Work Vulnerable to Challenge Splicing and Replay in github.com/altcha-org/altcha-lib-go...

CVE-2025-68113

CVE-2025-68113 (ALTCHA) describes a cryptographic semantic binding flaw in ALTCHA libraries where the HMAC does not unambiguously bind challenge parameters to the nonce, enabling potential replay of previously solved challenges depending on server-side handling. Affected components include ALTCHA...

CVE-2025-68113 ALTCHA Proof-of-Work Vulnerable to Challenge Splicing and Replay

ALTCHA is privacy-first software for captcha and bot protection. A cryptographic semantic binding flaw in ALTCHA libraries allows challenge payload splicing, which may enable replay attacks. The HMAC signature does not unambiguously bind challenge parameters to the nonce, allowing an attacker to...

ALTCHA Proof-of-Work Vulnerable to Challenge Splicing and Replay

Impact A cryptographic semantic binding flaw in ALTCHA libraries allows challenge payload splicing, which may enable replay attacks. The HMAC signature does not unambiguously bind challenge parameters to the nonce, allowing an attacker to reinterpret a valid proof-of-work submission with a modifi...

ALTCHA Proof-of-Work Vulnerable to Challenge Splicing and Replay

A cryptographic semantic binding flaw in ALTCHA libraries allows challenge payload splicing, which may enable replay attacks. The HMAC signature does not unambiguously bind challenge parameters to the nonce, allowing an attacker to reinterpret a valid proof-of-work submission with a modified...

CVE-2025-65849

A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the Proof-of-Work nonce in constant time via mathematical deduction. NOTE: this is disputed by the Supplier because the product's objective is "to discourage automated...