Vulnerability | Breaking Cybersecurity News | The Hacker News

A single hacked device on a Tailscale network can be used to gain root access to other servers it can reach, according to a security researcher who published the findings this week. The attack requires two things: Tailscale SSH set up to allow port forwarding, and an attacker who already controls one device that the network's access rules permit to connect to the target. The findings were published on October 25 in a report called  Tailworm  by Erica Windisch of Cyberdione Labs. Windisch tested Tailscale version 1.104.2 and headscale version 0.29.5, the self-hosted server some networks use to run Tailscale instead of the company's hosted service, over three days in a lab. The report describes tests on that software, not attacks against real networks. As of publication, Tailscale had issued no  security bulletin , no CVE identifier, and no fixed version. Tailscale has responded in public. Mike Shaver, the company's vice president of engineering,  wrote on Red...

In an update, Palo Alto Networks Unit 42 said it's retracting its earlier assessment that the post-compromise activity targeting the European government agency involved the exploitation of the PHP2Shell flaws. "What researchers saw was an attack against a European government agency executed in the context of a vulnerable PHP application," a spokesperson for the company told The Hacker News via email. "This led us to believe that it was exploitation of those vulnerabilities. We are unable to confirm that initial access is associated with the specific PHP2Shell CVEs." The original story follows. Threat actors have been observed using agentic artificial intelligence (AI) platforms for post-exploitation activity following the abuse of the PHP2Shell vulnerabilities tracked as CVE-2026-109618 and CVE-2026-109619. "In one case, the attackers targeted a government entity in Europe and within two hours of the initial exploitation they had successfully acce...

OpenAI has announced plans to conduct frontier model training with no live internet access, as it resumes reinforcement learning (RL) training and internal inference of its most advanced AI models. "Based on the current state of alignment research, monitoring systems, and the security of internet infrastructure, we believe the responsible approach is to conduct frontier model training with no internet access," the artificial intelligence (AI) company said . "We've implemented this policy and will maintain it until advances in these safeguards justify broader internet access." OpenAI said models' growing capabilities can have the side effect of them getting much better at devising ways around environmental restrictions to escape containment and perform unintended actions. This can involve the model exploiting a software flaw or misconfiguration to reach the live internet, or finding unauthorized ways to communicate with agents in other sandboxes. Late ...

A memory-corruption flaw in Google's Brotli decoder sits in many programs that unpack Brotli-compressed data, among them Bun, the Python Brotli and brotlicffi packages, and Envoy proxies set up to decompress Brotli. Tracked as  CVE-2026-111497 , the flaw allows crafted compressed data to overwrite past the end of a buffer and corrupt a program's memory, potentially causing a crash, a memory leak, or the execution of attacker-controlled code. Imperva researchers have shown that code can run on one unpatched Node.js build . The same has not been demonstrated on the other software, and no real-world attacks have been reported. The flaw was  first disclosed on October 21 , when Node.js and Google shipped fixes, and more have followed product by product since. Because the bug is in Google's decoder and each program ships its own copy of it, every one has to update that copy on its own. Brotli is a compression format from Google, used across the web to ...

Between November 2025 and March 2026, the Dutch security firm Eye Security pushed more than 2 million updates to computers it did not own to switch off a background updater that it said could have allowed an outsider to take over the machine. The updater belongs to Time4Popcorn , an abandoned copy of Popcorn Time, a free app that streamed pirated films and TV over BitTorrent. Popcorn Time was popular about a decade ago, and the original shut down in 2014, but several copies kept running under the same name. A separate, legal project that took the Popcorn Time name in early 2025 is unrelated to it. Eye Security, which monitors client networks for threats, found the updater during a routine threat hunt: a program called Updater.exe on one client's laptop kept trying to reach a web address that was no longer registered. The firm registered the address itself to see what would connect, and about 50 requests a second poured in. It later laid out the operation, which it named ...