CVE WatchJul 27, 2026

CVE-2026-59250

Classic buffer overflow in the Erlang/OTP megaco flex scanner C driver allows a remote unauthenticated attacker to corrupt the driver's memo

CVSS

—

No CVSS

EPSS

—

KEV

—

Exploit Today

—

0-100

Published: Jul 27, 2026 · Last modified: Jul 27, 2026 · CWE-120 · CWE-787

EPSS · 30d

Not enough EPSS history yet.

Technical description

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 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to megaco from 3.17.1 before 4.9.1, 4.8.3.1 and 4.7.2.2. Versions prior to OTP 17.0 are also affected but are not listed because the OTP version scheme is only defined from OTP 17.0 onwards.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-55737—

—

———Signed to Unsigned Conversion Error and Out-of-bounds Write vulnerability in Erlang OTP erts allows an attacker who can supply a crafted Erlang external term format (ETF) binary to binary_to_term/1 to corrupt the BEAM heap pointer and crash the virtual machine. When decoding a LARGE_TUPLE_EXT term, the validation pass decoded_size() in erts/emulator/beam/external.c reads the 32-bit arity field as unsigned (get_uint32()), while the decode pass dec_term() reads the same field as a signed 32-bit integer (get_int32()) into an int. An arity wire value of 0x80000000 passes validation as 2147483648 but decodes as -2147483648, so the subsequent hp += n moves the heap allocation pointer backward. Neither pass enforces the runtime tuple-arity limit MAX_ARITYVAL. The result is an out-of-bounds heap write; in practice the VM detects an impossible heap size and aborts, denying service. The required padding is large when uncompressed but the compressed-ETF envelope shrinks it to a small payload on the wire. This issue affects OTP from OTP 25.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to erts from 13.0 before 17.0.4, 16.4.0.4 and 15.2.7.11.5h CVE-2026-17572—

—

———Heap-based buffer overflow in the SOHM list-index deserialization code in HDF5 through 2.1.1 on all platforms allows attackers to cause a denial of service (crash) via a crafted HDF5 file whose shared-message list index declares a num_messages count exceeding list_max, triggering out-of-bounds heap reads and writes in H5SM__cache_list_deserialize and H5SM__cache_list_verify_chksum.5h CVE-2026-660418.8 HIG

34.7%

——10FFmpeg 7.0 through 8.1.2, fixed in commit 4da9812, contains a heap out-of-bounds write vulnerability in the vf_quirc filter that allows an attacker to corrupt heap memory by supplying a crafted PGS/SUP subtitle file with mismatched frame dimensions. Attackers can provide a subtitle file whose second presentation has larger dimensions than its first, causing av_image_copy_plane() to copy data exceeding the initial allocation size into the undersized libquirc grayscale image buffer, resulting in heap corruption and process crash with potential for code execution.3d CVE-2026-458138.8 HIG

19.5%

——6Out-of-bounds Write, Integer Underflow (Wrap or Wraparound) vulnerability in Apache NimBLE BASS service. Improper validation when parsing BASS service "Add Source" and "Modify Source" operation PDU could results in stack buffer overflow or arbitrary out-of-bound read. This can be triggered by nearby devices over Bluetooth connection, however pairing is required prior to accessing BASS service, which depending on device configuration may or may not require user action. This issue affects Apache NimBLE: through 1.9.0. Users are recommended to upgrade to version 1.10.0, which fixes the issue.6h CVE-2026-458117.5 HIG

16.8%

——5Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Apache NimBLE. The HCI socket transport did not check whether a received HCI event would fit the configured event pool before copying it, allowing a buffer overflow. Severity is low: exploitation requires either a misconfigured pool size or a malicious/compromised controller on the other end of the HCI socket link, not over-the-air Bluetooth access. This issue affects Apache NimBLE: through 1.9.0. Users are recommended to upgrade to version 1.10.0, which fixes the issue.6h CVE-2026-168708.8 HIG

28.8%

——9Multiple security vulnerabilities in Snowflake libsnowflakeclient versions prior to 2.9.2 could allow remote code execution and credential exfiltration. A stack-based buffer overflow in the file download path could allow remote code execution on a victim host. An attacker could exploit this by uploading a file with a crafted encryption metadata field to a shared internal stage that a victim process later downloads, and impact would be limited to deployments where principals with different privilege levels share the same internal stage. A related out-of-bounds write in the same download path could allow memory corruption with attacker-controlled write primitives. An attacker may exploit this through a crafted initialization vector metadata field on a shared stage, and impact would be limited by the same stage-write precondition. Improper validation of connection parameters could allow an attacker-controlled input to redirect outbound authentication requests — including credentials and tokens — to an attacker-controlled endpoint. Impact is limited to embedding deployments where a lower-privileged principal can influence connection configuration while higher-privileged service credentials are in use. The fix is available in Snowflake libsnowflakeclient version 2.9.2. The Snowflake PHP PDO Driver and Snowflake ODBC Driver embed the affected library; fixes are available in versions 4.1.0 and 3.19.0 respectively. Users must manually upgrade.3d