New Spectre-v2 Variant Uses JIT Compiler Branch Target Reuse for Cross-Process Data Extraction
Researchers from the Netherlands and Italy have published a scientific paper describing a new attack belonging to the Spectre-v2 class. The original Spectre-v2 technique, demonstrated in 2018, exploits the branch prediction mechanisms in modern CPUs to execute a chosen malicious instruction and then read its results from cache via a side channel.
The new research replaces instruction injection with a method that reuses existing information inside the branch predictor. The required Branch Target Reuse state is created by the operation of a JIT compiler, a scenario previously considered impractical for attacks. The published study demonstrates successful secret extraction when branch prediction features are combined with the cBPF JIT compiler present in the Linux kernel.
The same researchers also examined the SpiderMonkey JIT compiler used in Firefox and the GraalVM engine. The JIT compiler was employed to train the branch predictor, while the actual attack became possible when different code was loaded at the same memory addresses. This created conditions for speculative execution that granted access to secret data.
A practical demonstration targeted the su process on Linux and extracted the hashed root password from CPU cache. The required result was achieved in an average of three to five minutes, which is relatively fast for complex Spectre-class attacks. A full attack was shown using the cBPF compiler. With SpiderMonkey and GraalVM only partial success was recorded: branch predictor training was possible, yet realistic attacks could not be demonstrated.
The researchers confirmed that the attack works on all major modern CPU types, including AMD, Intel, and ARM architectures.
What else happened
Specialists from Kaspersky published an analysis of methods for detecting traces of attacks against 1C servers, extending their earlier research on real incidents. Last week Debian released a record kernel update addressing more than 1,300 vulnerabilities. Dangerous flaws were found in both client and server components of TeamViewer. A zero-day vulnerability in Core Graphics was fixed in iOS and macOS updates. Google closed its bug bounty program for open-source projects it supports due to the large volume of automatically generated reports produced by AI assistants. Critical vulnerabilities were also disclosed in Dell Container Storage Modules, including two issues with a maximum CVSS score of 10 that allow authentication bypass.
Related articles
Critical PHP Vulnerabilities CVE-2026-109618 and CVE-2026-109619 Enable Unauthenticated Remote Code Execution
Two critical vulnerabilities in PHP, tracked as CVE-2026-109618 and CVE-2026-109619, both scoring CVSS 9.2, were disclosed on October 21. The flaws allow attackers to execute arbitrary code without authentication by triggering out-of-memory conditions that lead to use-after-free memory corruption. Exploitation involves specially crafted requests that manipulate uninitialized arrays and function pointers, with full chains demonstrated via PHP_SESSION_UPLOAD_PROGRESS and fatal error backtraces. The issues affect PHP versions starting from 5.4 and were discovered using AI tools Gemini 4 Argon and GPT-5.6 Sol, resulting in a patch exceeding 10,000 lines of code. Amazon detected attacks as early as October 17, with Cloudflare later reporting millions of exploitation attempts. Mitigation requires updating to patched versions such as PHP 8.2.35, 8.3.36, 8.4.27 or 8.5.12, while temporary workarounds include disabling session upload progress and fatal error backtraces.
Trend Micro ZDI Reports on Critical Linux KSMBD Vulnerabilities Leak to Public Mailing Lists Before Patches
Trend Micro Zero Day Initiative inadvertently published detailed vulnerability reports for the Linux kernel's KSMBD component into public mailing lists. Two flaws received CVSS scores of 9.0, enabling remote code execution under specific conditions. One issue involves a race condition during parallel SMB request handling, while the second stems from an incorrect buffer size calculation in the SMB Direct mechanism that requires RDMA and a writable share. Technical details including root causes and reproduction steps became publicly archived before fixes reached end users. The KSMBD maintainer has already merged a patch for ZDI-CAN-33774 into their repository, yet distribution kernels may still lack the update. Additional privilege-escalation and information-disclosure risks in other kernel components were also described in the leaked messages.
Node.js Issues Security Releases for 26.x, 24.x and 22.x Fixing High-Severity TLS and Brotli Flaws
Node.js published security updates on October 21, 2026 for the 26.x, 24.x and 22.x release lines. The patches address multiple high-severity vulnerabilities affecting TLS hostname validation and the Brotli decoder, along with updates to critical dependencies including OpenSSL and Undici. Several CVEs cover bypasses in certificate hostname checks when IP addresses use full-width digits or when hosts resolve loosely to IP addresses. A particularly serious out-of-bounds write in the Brotli decoder (CVE-2026-111497) could enable remote code execution on services processing compressed responses. Additional fixes resolve keep-alive socket timing issues, DNS resolution truncation with NUL characters, and entropy caching problems in crypto.randomUUID and randomInt functions. The releases also update c-ares, Undici, OpenSSL, SQLite and ca-cert bundles following the eMudhra intermediate CA compromise.
Atlassian October Security Bulletin Flags 176 Third-Party Library Vulnerabilities Across Jira, Confluence and Bitbucket
Atlassian released its October security bulletin detailing 176 vulnerability entries distributed across seven products including Jira, Confluence, Bamboo, Bitbucket, Crowd, Fisheye and Crucible. Of these, 162 entries carry high severity and 14 are rated critical, though the total does not represent 176 unique flaws because the same identifiers recur when multiple products share the same third-party library. All critical issues originate in external components rather than Atlassian code, with the most severe being CVE-2026-65637 in the Coyote component of Apache Tomcat used by Confluence, which allows interception of server-client connections. Affected versions and corresponding fixes were published for Confluence Data Center, Bamboo, Bitbucket Data Center, Jira Software and Jira Service Management, with the company stressing that administrators must compare exact build numbers against the full corrected-version table. No exploitation of the listed issues had been reported as of 22 October, and Atlassian classifies the inherited exposure from third-party libraries as lower priority, issuing separate critical alerts only for immediate-risk cases.