usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb() The block_len read from the host-supplied NTB header is checked against ntb_max but has no lower bound. When block_len is smaller than opts->ndp_size, the bounds check of: ndp_index > (block_len - opts->ndp_size) will underflow producing a huge unsigned value that ndp_index can never exceed, defeating the check entirely. The same underflow occurs in the datagram index checks against block_len - opts->dpe_size. With those checks neutered, a malicious USB host can choose ndp_index and datagram offsets that point past the actual transfer, and the skb_put_data() copies adjacent kernel memory into the network skb. Fix this by rejecting block lengths that cannot hold at least the NTB header plus one NDP. This will make block_len - opts->ndp_size and block_len - opts->dpe_size both well-defined. Commit 8d2b1a1ec9f5 ("CDC-NCM: avoid overflow in sanity checking") fixed a related class of issues on the host side of NCM.

net/x25: Fix overflow when accumulating packets

In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix overflow when accumulating packets Add a check to ensure that `x25_sock.fraglen` does not overflow. The `fraglen` also needs to be resetted when purging `fragment_queue` in `x25_clear_queues()`.

MOOS essential-moos through 10.0.1 pMOOSBridge Heap Corruption via Negative UDP Length

MOOS essential-moos through 10.0.1 contains a buffer overflow vulnerability in CMOOSUDPLink::ReadPktFromArray() that allows remote attackers to corrupt heap memory by sending UDP datagrams with negative declared lengths. Attackers can send crafted UDP packets to the configured UDPListen port to trigger an oversized memcpy operation that writes past the destination buffer, causing heap corruption and denial of service.

Unvalidated Input in Siemens APOGEE Web Service Enables Unauthenticated Remote Memory Read or Denial of Service

A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BACnet) (All versions), APOGEE MEC (PPC) (P2 Ethernet) (All versions), APOGEE PXC Compact (BACnet) (All versions < V3.5.7), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.21), APOGEE PXC Modular (BACnet) (All versions < V3.5.7), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.21), TALON TC Compact (BACnet) (All versions < V3.5.7), TALON TC Modular (BACnet) (All versions < V3.5.7). The affected product web service does not properly validate the length of user-controllable input. This could allow an unauthenticated remote attacker to read portions of device memory or to cause a denial-of-service condition.

Huawei malicious on-bus PLDM or NCSI device can drive out-of-bounds-heap reads via short MCTP responses

The openUBMC device-management process parses PLDM-over-MCTP and NCSI-over-MCTP responses from on-bus devices, and three response parsers in the shared transport libraries subtract a fixed header or reserved-field size from a device-supplied response length without a lower-bound check. An undersized response wraps the unsigned length difference to a very large value, and the parser then reads far past the response buffer. The affected code sits in the base (non-vendor) PLDM control class and the Huawei NCSI driver, so it is reachable for any PLDM endpoint or Huawei NIC on the internal management bus, unlike the vendor-specific wangxun parser tracked separately.

openldap: Integer underflow in issuerAndThisUpdateCheck in schema_init.c

An integer underflow was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Certificate List Exact Assertion processing, resulting in denial of service.

openldap: Integer underflow in serialNumberAndIssuerCheck in schema_init.c

An integer underflow was discovered in OpenLDAP before 2.4.57 leading to slapd crashes in the Certificate Exact Assertion processing, resulting in denial of service (schema_init.c serialNumberAndIssuerCheck).

glibc: signed comparison vulnerability in the ARMv7 memcpy function

An exploitable signed comparison vulnerability exists in the ARMv7 memcpy() implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets that utilize the GNU glibc implementation) with a negative value for the 'num' parameter results in a signed comparison vulnerability. If an attacker underflows the 'num' parameter to memcpy(), this vulnerability could lead to undefined behavior such as writing to out-of-bounds memory and potentially remote code execution. Furthermore, this memcpy() implementation allows for program execution to continue in scenarios where a segmentation fault or crash should have occurred. The dangers occur in that subsequent execution and iterations of this code will be executed with this corrupted data.

wstrncat() unsigned integer underflow leads to an off-by-one null write in wolfSSH on non-Windows platforms

Unsigned integer underflow in wstrncat() in src/port.c in wolfSSL wolfSSH from v1.4.11 through v1.5.0 on non-Windows platforms allows an authenticated remote attacker to write one out-of-bounds null byte past the end of a stack buffer by sending a crafted SFTP path. wolfSSH_RealPath() in src/ssh.c appends each path component with a remaining-size bound (outSz - curSz) rather than the full destination size, so once the accumulated path reaches half the output buffer the size_t computation n - strlen(s1) - 1 wraps to near SIZE_MAX. The strncat() call is then effectively unbounded and copies the whole component; when that component exactly fills the remainder of the buffer, its terminating null is written one byte past the end. The caller's own length check keeps the copied data inside the buffer, so the overflow is limited to that single null byte, which may corrupt an adjacent stack value and crash the process. Applications that call the public wolfSSH_RealPath() with an output buffer smaller than the input path are additionally exposed to an unbounded copy, because the word32 expression outSz - segSz in that length check also wraps.

Memory Corruption vulnerability in SAP NetWeaver and SAP Web Dispatcher (Internet Communication Manager)

SAP NetWeaver and SAP Web Dispatcher do not properly validate certain fields in specially crafted requests handled by an internal protocol component. An unauthenticated attacker could send a malicious request that triggers a memory-handling error, causing the affected process to crash. Successful exploitation can therefore result in a high impact on the availability of the affected application. There is no impact on the confidentiality or integrity of the application.

Improper Authorization check in SAP Cloud Connector

SAP Cloud Connector contains an improper authorization check, which could be exploited by a low-privileged attacker through specially crafted requests. Exploitation requires the attacker to be on an adjacent network. Successful exploitation could allow the attacker to obtain limited information about internal systems, resulting in low impact on confidentiality. There is no impact on integrity and availability.

odhcpd: pre-auth remote DoS via size_t underflow in dhcpv6_ia_handle_IAs (stack BOF, canary-terminated)

odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In commit cfddd56 and earlier, an unauthenticated host on the same link can first obtain two bindings through normal DHCPv6 SOLICIT and REQUEST exchanges and then send a crafted RENEW containing multiple IA_NA options. An earlier matched IA consumes most of the response buffer, an unmatched IA causes the build_ia() status branch to write and return a NOBINDING response larger than the remaining space, and a subsequent matched IA is processed after dhcpv6_ia_handle_IAs() subtracts that over-return from an unsigned size_t. The resulting underflow disables subsequent length checks and permits attacker-controlled IA_ADDR serialization beyond the 512-byte stack buffer pdbuf in handle_client_request(). The stack canary terminates odhcpd, and sustained packets can repeatedly disrupt DHCPv6 service while procd respawns the process. The observed configuration does not establish code execution.

OpENer v2.3/commit 76b95cf, contains an integer underflow in the server-side EtherNet/IP ForwardOpen connection-path parser. This allows a remote attacker to cause a denial of service

RIOT: nanoCoAP Block2 client slice handling underflows on inconsistent server-controlled block size

RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. In 2026.07 and earlier, the nanoCoAP client function nanocoap_sock_get_slice() in sys/net/application_layer/nanocoap/sock.c accepts a Block2 response when _block_cb() sees the expected block number without also verifying that the server-controlled szx and derived offset match the requested block geometry. A malicious CoAP server can return the expected block number with a larger block size, causing the derived offset to exceed the client slice offset and making ctx->offset - offset underflow in _2buf_slice(). The resulting buffer-relative calculation can read before the payload buffer and crash the client, causing denial of service and potentially exposing adjacent memory. No fixed release is available as of this review.

Security Advisory 0194

On affected Arista Wi-Fi access points with Captive Portal enabled, an unauthenticated wireless client connected to a Captive-Portal-enabled SSID can crash the portal service with a crafted HTTP request. This results in a temporary denial of service until the service automatically restarts. Remote code execution is not possible.

Integer underflow in TightVNC Server cursor shape trimming leads to out-of-bounds read

An integer underflow in WinCursorShapeUtils::trimTransparent() in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to crash the server, and potentially read out-of-bounds memory, by causing a cursor shape with a width or height of zero to be processed on the DXGI capture path. The loop bound width - 1 wraps to 0xFFFFFFFF, producing an access roughly 4 GB beyond the 64 KB cursor buffer; a monochrome cursor of height 1 also becomes 0 because getCursorHeight() halves the height in place.

An Integer underflow in VLC Media Player versions < 3.0.7 leads to an out-of-band read.

An Integer Underflow in MP4_EIA608_Convert() in modules/demux/mp4/mp4.c in VideoLAN VLC media player through 3.0.7.1 allows remote attackers to cause a denial of service (heap-based buffer overflow and crash) or possibly have unspecified other impact via a crafted .mp4 file.

kernel: Integer underflow when restricting speculative pointer arithmetic

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.

Application denial of service via malformed KMS endpoint in MongoDB libmongocrypt

An integer underflow in the KMS endpoint-parsing logic of MongoDB libmongocrypt can cause an allocation failure that terminates the application process. This can occur when an authenticated user modifies a key document in the key vault collection, or when an application accepts a KMS endpoint containing a colon after its path or query during key creation. The issue does not access memory outside its allocated bounds.