CVE-2026-59250
HighCVSS 8.3Exploitation Probability (EPSS)
Elevated risk55th percentile - higher than 55% of all known CVEs
Summary
A classic buffer overflow in the Erlang/OTP megaco flex scanner C driver allows a remote unauthenticated attacker to corrupt the driver's memory (potentially leading to remote code execution or denial of service) by sending a single H.248/Megaco message with an oversized property name. The flaw occurs in mfs_load_property_groups, which uses an unchecked sprintf to write into a fixed 512-byte error_msg field, overwriting adjacent struct fields and enabling arbitrary write and free primitives in the BEAM VM process.
Risk Assessment
The organization is exposed to remote code execution or denial of service by a network attacker without authentication, requiring only reachability to the megaco port on a node configured with {scanner, flex}.
Recommendation
Immediately upgrade Erlang/OTP to version 27.3.4.15, 28.5.0.4, or 29.0.4 (or later) and correspondingly megaco to 4.7.2.2, 4.8.3.1, or 4.9.1. If upgrading is not possible, restrict access to the megaco port to trusted hosts only.
Related vulnerabilities
- CVE-2026-123025Critical
An OS command injection vulnerability was discovered in the Google Cloud DNS validation module of the OPNsense os-acme-client plugin through 4.17. The DnsGcloud::prepare() method decodes the dns_gcloud_key model field and directly interpolates the gcloud_account and gcloud_project string fields into a shell command passed to proc_open() via LeUtils::run_shell_command() without validation or escaping. A remote authenticated user with privileges to issue or renew certificates through the WebGUI/API can achieve arbitrary code execution as root.
- CVE-2026-122992Critical
In G4KLX DStarGateway and F4FXL DStarGateway before 7b75de6, dstarCallsignToAPRS in APRSUtils.cpp has an integer underflow via an empty RS-MS1A sender field.
- CVE-2026-122321Critical
Kyverno 1.18.0 before 1.19.2 contains a signature verification bypass in verifyImages because cached verification results are keyed by the image reference string (such as a tag) rather than bound to the verified digest, so cache hits skip signature and attestation checks. An attacker who can submit workloads and move a registry tag can warm the cache with a signed image, repoint the tag, and have Kyverno admit the workload and use mutateDigest to pin the unverified digest.
- CVE-2026-122313Critical
Kyverno from 1.17.0 before 1.19.2 contains a privilege escalation vulnerability that allows namespace-scoped tenants to modify resources in other namespaces through NamespacedMutatingPolicy targetMatchConstraints.expression CEL output lacking namespace checks. Attackers can emit a literal target such as another tenant's RoleBinding, which the cluster-wide background controller then mutates to add attacker subjects or alter Roles, NetworkPolicies, and ConfigMaps.
- CVE-2026-122311Critical
Kyverno from 1.16.0 before 1.19.2 fails to validate path segments in the resource argument of resource.get() and resource.post(), allowing namespaced CEL policies to escape their namespace. Tenants who can create a NamespacedValidatingPolicy can insert .. segments to read and write arbitrary cluster objects using the admission controller's ServiceAccount, leading to cluster takeover.
- CVE-2026-122310Critical
Kyverno from 1.19.1 before 1.19.2 validates a Policy's context.apiCall urlPath after cleaning it but executes the raw path, whose fragment or query the Kubernetes client discards. A namespace-scoped user who can create a Policy can hide ../ segments behind # or ? to reach cluster-scoped endpoints with Kyverno's ServiceAccount, gaining cluster admin.
- CVE-2026-122304Critical
Kyverno from 1.17.0 before 1.19.2 contains an authorization bypass vulnerability that allows namespace admins to escape namespace confinement because the cleanup controller builds its context loader with a nil policy. Attackers can create a namespaced CleanupPolicy with apiCall or globalReference context entries to read cross-namespace Secrets and modify validatingwebhookconfigurations using the cleanup controller's ServiceAccount.
- CVE-2026-122303Critical
Kyverno from 1.17.0 before 1.19.2 contains an authorization bypass vulnerability that allows namespace tenants to overwrite resources in other namespaces via NamespacedMutatingPolicy mutate-existing targetMatchConstraints.expression. Attackers can return a CEL map literal fabricating a target with an attacker-chosen metadata.namespace, causing the privileged background controller to overwrite Secrets, Deployments, or policies cluster-wide.
- CVE-2026-122302Critical
Kyverno before 1.19.2 contains a privilege escalation vulnerability that allows namespace admins to create resources beyond their RBAC because generate-rule admission checks verify the controller's permissions, not the author's. Attackers can create a namespaced Policy with generate rules targeting other namespaces or cluster-scoped kinds, making the background controller create or clone resources cluster-wide.
- CVE-2026-122051Critical
A flaw was found in Edimax BR-6208AC version 1.32 in an unknown functionality of the /goform/mp file. Input manipulation can lead to command injection. The attack can be launched remotely and the exploit has been published.
Original NVD description (English source)
Classic buffer overflow in the Erlang/OTP megaco flex scanner C driver allows a remote unauthenticated attacker to corrupt the driver's memory (and potentially achieve remote code execution or a denial-of-service crash) by sending a single text-encoded H.248/Megaco message containing an oversized property parm name. When tokenizing a Local/Remote descriptor, mfs_load_property_groups extracts the attacker-controlled property name (bounded only by the message length) and, when no value follows, formats it into a fixed 512-byte error_msg field of the MfsErlDrvData struct using an unchecked sprintf call. Names longer than roughly 452 bytes overflow into the immediately following struct fields (text_buf, text_ptr, term_spec, term_spec_size, term_spec_index), overwriting live pointers and counters with attacker-chosen bytes. Subsequent scanner code writes and frees through the corrupted pointers, producing arbitrary write and arbitrary free primitives inside the BEAM VM process, which can be leveraged for remote code execution. On builds compiled with _FORTIFY_SOURCE the overflow is detected at runtime and terminates the process with SIGABRT, resulting in denial of service. The overflow occurs in the flex scanner before any grammar or Megaco-level authentication processing, so exploitation requires only network reachability to the megaco transport port on a node configured with {scanner, flex}. This vulnerability is associated with program files lib/megaco/src/flex/megaco_flex_scanner_drv.flex.src and program routines mfs_load_property_groups. This issue affects OTP from OTP 17.0 before OTP 27.3.4.15, from OTP 28.0 before OTP 28.5.0.4, and from OTP 29.0 before OTP 29.0.4, corresponding to megaco from 3.17.1 before 4.7.2.2, from 4.8 before 4.8.3.1, and from 4.9 before 4.9.1. Whether OTP before OTP 17.0, corresponding to megaco before 3.17.1, is affected is unknown.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

