30
Zombie Card Attack Can Revive Expired Visa Cards for Contactless Payments
UMass Amherst researchers demonstrate Zombie Card, an NFC relay attack that revives expired Visa contactless cards for in-store purchases without breaking cryptography.
Researchers at the University of Massachusetts Amherst presented the Zombie Card attack at USENIX Security 2026, showing that Visa's Kernel 3 does not cryptographically bind the Application Expiration Date (tag 5F24) the terminal reads with the Track 2 expiry seen by the issuer. By positioning an NFC man-in-the-middle relay, an attacker can rewrite the terminal-facing expiration date of an expired card and complete contactless purchases, provided the account remains open under the same PAN and the bank does not independently re-check expiry. Testing across five major US banks found three distinct policies; Visa Kernel 3 accepted the modified date, while Mastercard, American Express, and Discover kernels declined modified transactions. Findings were disclosed to Visa and affected banks in May 2025, no CVE has been assigned, and no exploitation has been reported.
58
Researchers find a loophole that lets expired credit cards make unauthorized payments
UMass Amherst researchers showed at USENIX Security 2026 that NFC relay attacks can rewrite unprotected expiration dates, letting expired Visa contactless cards keep making payments.
UMass Amherst researchers presented the Zombie Card attack at USENIX Security 2026, using two smartphones to relay and modify NFC payment data from expired Visa cards. The expiration date lies outside the card's digital signature coverage in Visa Kernel 3, and one major US bank accepted $1-$500 test purchases plus live $2.79 and $3.19 purchases with rewritten dates. Mastercard, American Express, and Discover rejected tampered dates; researchers notified Visa in May 2025 and no CVE or confirmed fix existed at publication.
40
LG smart TVs caught logging audio with screen off and snooping on local devices
Gamers Nexus found LG smart TVs record microphone audio in standby, scan home networks, and feed LG Ad Solutions ad targeting.
A 135-minute Gamers Nexus investigation with Level1Techs and independent researchers found retail LG OLED TVs running webOS sweep local networks, gather device names and Wi-Fi metadata, and run Automated Content Recognition. Tests showed the TVs capture clean microphone audio while appearing powered down and store it offline, uploading once reconnected. The team also found RCE vulnerabilities in webOS now moving through responsible disclosure; LG claims 216 million smart TV sales, and its ad unit claims access to 363 million addressable devices in the US.
40
Getting a stranger’s phone kicked off the cellular network costs a few dollars
Researchers show attackers can remotely block strangers' phones and alarm gateways on US cellular networks by abusing lost/stolen IMEI reporting for $2.50-$4 per device.
Researchers from Michigan State University and three partner schools found six weaknesses in the lost/stolen device reporting ecosystem spanning devices, carrier systems, and cross-carrier block-list sharing. They demonstrated blocking unopened Samsung Galaxy Z Fold 7 phones and home alarm gateways on three major US carriers, with each block costing $2.50-$4 and taking roughly 20-80 seconds. The attacks exploit thin identity and ownership checks in prepaid accounts, IMEI leakage from vulnerable cellular chipsets used by two vendors with over 40% global market share, and pre-release IMEI databases purchasable for $600. Victims receive no notification, and restoring service requires proving device ownership to the carrier.
55
New GPUThor Rowhammer Defeats ECC on NVIDIA RTX A6000 to Gain Host Root Access
University of Toronto researchers present GPUThor, a Rowhammer attack that defeats ECC on NVIDIA RTX A4000-A6000 GDDR6 GPUs and achieves host root access.
GPUThor uses non-uniform hammering to bypass Target Row Refresh and overcome SECDED ECC on NVIDIA Ampere workstation GPUs with GDDR6 memory, inducing 72,000 to 377,552 bit flips per gigabyte across RTX A6000, A5000, A4500, and A4000 cards. Triple-bit silent data corruption enables host privilege escalation to root with the IOMMU enabled, reusing GPUBreach page-table corruption techniques, and double-bit DUEs allow escalation when the IOMMU is disabled during a ~10 ms lazy-service window. The attack cut end-to-end escalation time on the A6000 from 21.9 hours to 1.1 minutes. Reported to NVIDIA, Google, Microsoft, and AWS on April 29, 2026; findings were embargoed until August 25, 2026, and no CVE identifier was assigned.
62
Your Shredded Visa Card May Still Work at the Checkout
UMass Amherst researchers demonstrated expired Visa contactless cards can complete real purchases via relay attacks exploiting Visa Kernel 3's unsigned expiry date handling.
University of Massachusetts Amherst researchers presented at USENIX Security 2026 that expired Visa contactless cards can be revived for real purchases through an NFC man-in-the-middle attack on Visa's Kernel 3. The attack alters the expiry date the terminal sees (tag 5F24) while leaving the Track 2 Equivalent Data (tag 57) sent to the issuing bank unchanged, and the card's cryptographic signature does not cover the expiry date. Two Android phones emulating card and terminal relayed transactions within Visa's 500-millisecond limit. Mastercard, American Express, and Discover kernels blocked the attack, while Visa Kernel 3 did not; researchers also modified the Consumer Device Cardholder Verification Method flag at five US banks, and attackers can also exploit Terminal Verification Results zero-filling. Visa was notified in May 2025 and December 2025; no CVE has been assigned.
65
CDN Tsunami Attack Abuses HTTP/3 Translation for Up to 350x DoS Amplification
Researchers disclosed two DoS attacks exploiting CDNs' HTTP/3-to-HTTP/1.1 translation to amplify low-bandwidth requests up to 350x against origin servers.
Researchers named the two techniques HTTP/3 Bandwidth Amplification (HBA) and HTTP/3 Connection Amplification (HCA), exploiting the gap where CDNs speak HTTP/3 to browsers but only HTTP/1.1 to origins. All six tested CDNs (Alibaba, Baidu, Cloudflare, CloudFront, Fastly, Tencent) were susceptible to HBA, and five to HCA, with Cloudflare immune to HCA because it buffers full requests before opening backend connections. Attackers using under 5 Mbps forced over 100 Mbps at origins, and the 350x factor applies only to Alibaba, Baidu, and Tencent, which support the QPACK dynamic table. Testing identified 42,330 potentially vulnerable subdomains out of 151,685 hosted on the six providers across the Tranco Top 1M.
65
New DDRop Attack Breaks Intel TDX and AMD SEV-SNP Confidential Computing
DDRop uses a sub-$200 DDR5 interposer to drop memory writes, breaking Intel TDX and AMD SEV-SNP confidentiality guarantees.
Researchers at KU Leuven, ETH Zurich, Durham University, and Google will present DDRop at ACM CCS 2026, a first active interposer attack on DDR5 that silently drops memory writes so processors keep reading stale encrypted data, exploiting the missing freshness guarantee in Intel TDX, Intel Scalable SGX, and AMD SEV-SNP. On Intel TDX's default logical integrity mode it enabled reading victim VM memory, toggling debug mode, and forging remote attestation; AMD SEV-SNP was limited to copying pages between VMs. TDX's stronger cryptographic integrity blocks cross-VM attacks but likely not attestation forgery. The team will release board designs, firmware, and attack code on GitHub; no evidence of real-world use exists and no simple patch is available.
55
LG TV shown scanning LAN for third-party phones and other devices
Security researchers showed LG OLED TVs scan local networks and collect nearby device details, raising privacy concerns for TV owners.
Gamers Nexus, working with Level1Techs and security researchers, used packet captures and Wireshark to show that LG TVs, including the $2,500 OLED65G3PUA and the G5 OLED, scan the local network for phones, smartwatches, and other unconnected devices. The TV's firmware can identify the user's IP address, nearby Wi-Fi network names and signal strength, neighboring channel numbers, and internal IP addresses of other devices. LG Ad Solutions marketing claims reach of 363 million 'addressable secondary devices' in the US, and LG says the scanning supports device connectivity and smart home features. It remains unclear whether the collected data is transmitted to LG for purposes beyond advertising.
42
30
Risky Bulletin: Expired cards can be used for new transactions
Researchers show expired Visa contactless cards can be revived via NFC man-in-the-middle relay to run fraudulent transactions; roundup also covers major breaches.
University of Massachusetts Amherst researchers built an NFC man-in-the-middle rig that updates a card's expiration date in transit and relays the modified payment to POS terminals, reviving expired contactless cards; Visa terminals and the backends of all five banks studied failed to catch the manipulation. The same roundup reports Iranian hackers shut down a small UK power plant for four days, Lazarus breached South Korea's Presidential Office as part of a campaign exceeding 100 victims, and French telecom SFR suffered a breach affecting over 2.1 million customers.
55
Google Password Manager Attacks Could Let Malware Hijack Passkey
Unit 42 details three attack paths letting Windows malware silently sign into passkey-protected accounts via Chrome's Google Password Manager without user verification.
Palo Alto Networks Unit 42 described three post-compromise attack paths—Pass-ta-key, Silver Pass-ta-key and Golden Pass-ta-key—against Chrome's Google Password Manager cloud authenticator on TPM-equipped Windows systems. The attacks can silently obtain valid authentication assertions, install attacker-controlled user-verification keys, or extract the 32-byte Security Domain Secret used to decrypt synced passkey private keys, enabling reusable access from the attacker's own environment. No CVE was assigned and no exploitation in the wild was reported; demonstrations were validated against Chrome 142 and parts of the architecture are corroborated by Chromium source. GitHub enforced the User Verified flag check, while eBay accepted a test assertion lacking it before fixing its validation gap after disclosure.
55
30