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Daily Brief - 2026-08-16

· 4 vulnerabilities · 6 min listen

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CVE-2026-18500

high · CVSS 8.1 · Fastify @fastify/jwt

@fastify/jwt is a JSON Web Token plugin for Fastify. In versions before 10.2.2, a per-request verification key passed to request.jwtVerify({ key }) is silently overridden by the plugin's globally configured secret, because the option merge applies the global key last. Applications that use different keys for different authorization domains, for example separate user and admin keys, therefore accept a token signed with the global key on a route that explicitly requires another key. This lets an ordinary authenticated user cross a key-based trust boundary without knowing either secret. The issue is fixed in @fastify/jwt 10.2.2, where an explicit per-call key takes precedence over the global secret. Users should upgrade to 10.2.2.

  • Authentication Bypass
  • nodejs
  • web application

CVE-2026-72502

Linux Foundation Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: tcp: ipv6: clamp default adverting MSS to avoid GSO_BY_FRAGS (0xFFFF) When MTU is large, ip6_default_advmss() can return IPV6_MAXPLEN (65535). This is interpreted by TCP as mss_clamp, allowing the MSS to reach 65535. However, 0xFFFF is also used as a magic value GSO_BY_FRAGS in the kernel. If a TCP packet with gso_size=0xFFFF is passed to skb_segment(), it will be mistakenly treated as GSO_BY_FRAGS, leading to a NULL pointer dereference because local TCP packets do not use frag_list. Fix this by returning min(IPV6_MAXPLEN, GSO_BY_FRAGS - 1) (65534) from ip6_default_advmss() when MTU is large. Also update the stale comment in ip6_default_advmss() which suggested that IPV6_MAXPLEN is returned to mean "any MSS".

  • Denial of Service
  • linux kernel

CVE-2026-73194

Perl DBI

DBI versions before 1.652 for Perl allow a heap out-of-bounds write via an unvalidated numeric placeholder that sets the binder counter in preparse. preparse reserves seven output bytes per input byte, the width of the longest ':p99999' expansion. The ':N' branch parses the number with `atoi(src)` and assigns it to the binder counter with no range check, so a statement containing ':2147483648' leaves the counter negative (-2147483648 with glibc, where atoi wraps). Each following '?' then expands through `sprintf(start, ":p%d", idx++)` to ':p-2147483648', 14 bytes with the terminating NUL where the buffer budgets 7. The placeholder limit added in 1.650 tests the counter against 99,999, which a negative counter passes. Any caller that preparses an untrusted statement into ':pN' style placeholders gets a heap out-of-bounds write that grows with the number of '?' marks following the poisoned placeholder. The '?' and '%s' return styles compare the parsed number against the expected sequence and error out, and are unaffected.

  • Heap Out-Of-Bounds Write
  • perl library

CVE-2026-73635

Apache Software Foundation Struts

Allocation of resources without limits or throttling vulnerability in Apache Struts. When no fixed locale is configured, the locale used for localized-text lookups is taken from the incoming request, allowing an unauthenticated remote client to cause the framework's internal localized-text caches to grow without bound and exhaust the Java heap, denying service to other users. Applications that configure a fixed locale are not affected. This issue affects Apache Struts: from 2.0.0 through 2.3.37, from 2.5.0 through 2.5.33, from 6.0.0 through 6.10.0, from 7.0.0 through 7.2.1. Users are recommended to upgrade to version 6.11.0 or 7.3.0, which fixes the issue.

  • Denial Of Service
  • java
  • web framework