CyberSecBulletin

Buffer Copy without Checking Size of Input

CWE-120

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

We track 2,043 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.6. 24 have been exploited in real attacks.

How this weakness is prevented

  • Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Operation Build and Compilation: Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
  • Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Operation: Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.

Latest Buffer Copy without Checking Size of Input vulnerabilities

  • 8.6 High severity

    Firefox: Integer Overflow or Wraparound

    CVE-2026-4690Mozilla

    Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

  • 10.0 Critical severity

    Firefox: Integer Overflow or Wraparound

    CVE-2026-4689Mozilla

    Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

  • 8.6 High severity

    Firefox: Improper Check for Unusual or Exceptional Conditions

    CVE-2026-4687Mozilla

    Sandbox escape due to incorrect boundary conditions in the Telemetry component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

  • 8.8 High severity

    AC21: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-4565Tenda

    A vulnerability was detected in Tenda AC21 16.03.08.16. Impacted is the function formSetQosBand of the file /goform/SetNetControlList. Performing a manipulation of the argument list results in buffer overflow. The attack can be initiated remotely. The exploit

  • 8.8 High severity

    HiPER 1250GW: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-4488UTT

    A vulnerability was identified in UTT HiPER 1250GW up to 3.2.7-210907-180535. Affected is the function strcpy of the file /goform/setSysAdm. Such manipulation of the argument GroupName leads to buffer overflow. It is possible to launch the attack remotely. The

  • 8.8 High severity

    HiPER 1200GW: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-4487UTT

    A vulnerability was determined in UTT HiPER 1200GW up to 2.5.3-170306. This impacts the function strcpy of the file /goform/websHostFilter. This manipulation causes buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly

  • 9.8 Critical severity

    pyopenssl: Buffer Copy without Checking Size of Input

    CVE-2026-27459Pyca

    pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, if a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL

  • 8.8 High severity

    HiPER 810G: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-4318UTT

    A vulnerability was determined in UTT HiPER 810G up to 1.7.7-171114. Affected is the function strcpy of the file /goform/formApLbConfig. This manipulation of the argument loadBalanceNameOld causes buffer overflow. The attack can be initiated remotely. The expl

  • 7.3 High severity

    YAML::Syck: Heap-based Buffer Overflow

    CVE-2026-4177TODDR

    YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder co

  • 7.5 High severity

    BL-WR9000: Out-of-bounds Read

    CVE-2026-4227Lb-link

    A security vulnerability has been detected in LB-LINK BL-WR9000 2.4.9. The impacted element is the function sub_44D844 of the file /goform/get_hidessid_cfg. The manipulation leads to buffer overflow. It is possible to initiate the attack remotely. The exploit

  • 7.8 High severity

    GStreamer: Heap-based Buffer Overflow

    CVE-2026-3082GStreamer

    GStreamer JPEG Parser Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GStreamer. Interaction with this library is required to exploit this vulnera

  • 7.8 High severity

    GStreamer: Stack-based Buffer Overflow

    CVE-2026-3081GStreamer

    GStreamer H.266 Codec Parser Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GStreamer. Interaction with this library is required to exploit this

  • 8.1 High severity

    PX4-Autopilot: Buffer Copy without Checking Size of Input

    CVE-2026-32706PX4

    PX4 autopilot is a flight control solution for drones. Prior to 1.17.0-rc2, The crsf_rc parser accepts an oversized variable-length known packet and copies it into a fixed 64-byte global buffer without a bounds check. In deployments where crsf_rc is enabled on

  • 7.8 High severity

    GStreamer: Heap-based Buffer Overflow

    CVE-2026-2920GStreamer

    GStreamer ASF Demuxer Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GStreamer. Interaction with this library is required to exploit this vulnera

  • 9.8 Critical severity

    inetutils: Buffer Copy without Checking Size of Input

    CVE-2026-32746GNUEPSS 45.3%

    telnetd in GNU inetutils through 2.7 allows an out-of-bounds write in the LINEMODE SLC (Set Local Characters) suboption handler because add_slc does not check whether the buffer is full.

  • 7.8 High severity

    UNIX: Buffer Copy without Checking Size of Input

    CVE-2025-71263AT&T Bell Labs

    In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outs

  • 8.8 High severity

    iOS and iPadOS: Out-of-bounds Write

    CVE-2023-43010Apple

    The issue was addressed with improved memory handling. This issue is fixed in iOS 17.2 and iPadOS 17.2, macOS Sonoma 14.2, Safari 17.2, iOS 16.7.15 and iPadOS 16.7.15, iOS 15.8.7 and iPadOS 15.8.7. Processing maliciously crafted web content may lead to memory

  • 9.8 Critical severity

    Android: Buffer Copy without Checking Size of Input

    CVE-2026-0110Google

    In MM_DATA_IND of cn_NrSmMsgHdlrFromMM.cpp, there is a possible EoP due to memory corruption. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

  • 7.8 High severity

    Android: Buffer Copy without Checking Size of Input

    CVE-2025-48611Google

    In DeviceId of DeviceId.java, there is a possible desync in persistence due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

  • 7.8 High severity

    iccDEV: Buffer Copy without Checking Size of Input

    CVE-2026-31795InternationalColorConsortium

    iccDEV provides a set of libraries and tools for working with ICC color management profiles. Prior to 2.3.1.5, there is a stack buffer overflow write in CIccXform3DLut::Apply() corrupting stack memory or crash. This vulnerability is fixed in 2.3.1.5.

  • 7.8 High severity

    iccDEV: Buffer Copy without Checking Size of Input

    CVE-2026-30987InternationalColorConsortium

    iccDEV provides a set of libraries and tools for working with ICC color management profiles. Prior to 2.3.1.5, there is a stack buffer overflow in CIccTagNum<>::GetValues() causing stack memory corruption or crash. This vulnerability is fixed in 2.3.1.5.

  • 7.8 High severity

    iccDEV: Buffer Copy without Checking Size of Input

    CVE-2026-30985InternationalColorConsortium

    iccDEV provides a set of libraries and tools for working with ICC color management profiles. Prior to 2.3.1.5, there is a heap-based buffer overflow write in CIccMatrixMath::SetRange() causing memory corruption or crash. This vulnerability is fixed in 2.3.1.5.

  • 7.8 High severity

    iccDEV: Buffer Copy without Checking Size of Input

    CVE-2026-30983InternationalColorConsortium

    iccDEV provides a set of libraries and tools for working with ICC color management profiles. Prior to 2.3.1.5, there is a stack buffer overflow in icFixXml() (strcpy) causing stack memory corruption or crash. This vulnerability is fixed in 2.3.1.5.

  • 7.8 High severity

    iccDEV: Buffer Copy without Checking Size of Input

    CVE-2026-30979InternationalColorConsortium

    iccDEV provides a set of libraries and tools for working with ICC color management profiles. Prior to 2.3.1.5, there is a heap-based buffer overflow in CIccCalculatorFunc::InitSelectOp() triggered with local user interaction causing memory corruption/crash. Th

  • 8.8 High severity

    FortiSwitchAXFixed: Buffer Copy without Checking Size of Input

    CVE-2026-22627Fortinet

    A buffer copy without checking size of input ('classic buffer overflow') vulnerability in Fortinet FortiSwitchAXFixed 1.0.0 through 1.0.1 may allow an unauthenticated attacker within the same adjacent network to execute unauthorized code or commands on the dev

  • 8.8 High severity

    HiPER 810G: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-3815UTT

    A weakness has been identified in UTT HiPER 810G up to 1.7.7-1711. This affects the function strcpy of the file /goform/formApMail. Executing a manipulation can lead to buffer overflow. It is possible to launch the attack remotely. The exploit has been made av

  • 8.8 High severity

    HiPER 810G: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-3814UTT

    A security flaw has been discovered in UTT HiPER 810G up to 1.7.7-1711. Affected by this issue is the function strcpy of the file /goform/getOneApConfTempEntry. Performing a manipulation results in buffer overflow. It is possible to initiate the attack remotel

  • 8.8 High severity

    Magic B1: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-3701H3C

    A security vulnerability has been detected in H3C Magic B1 up to 100R004. Affected by this vulnerability is the function Edit_BasicSSID_5G of the file /goform/aspForm. Such manipulation of the argument param leads to buffer overflow. The attack can be executed

  • 8.8 High severity

    HiPER 810G: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-3700UTT

    A weakness has been identified in UTT HiPER 810G up to 1.7.7-171114. Affected is the function strcpy of the file /goform/formConfigDnsFilterGlobal. This manipulation causes buffer overflow. Remote exploitation of the attack is possible. The exploit has been ma

  • 8.8 High severity

    HiPER 810G: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-3699UTT

    A security flaw has been discovered in UTT HiPER 810G up to 1.7.7-171114. This impacts the function strcpy of the file /goform/formRemoteControl. The manipulation results in buffer overflow. The attack may be launched remotely. The exploit has been released to

  • 8.8 High severity

    HiPER 810G: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2026-3698UTT

    A vulnerability was identified in UTT HiPER 810G up to 1.7.7-171114. This affects the function strcpy of the file /goform/NTP. The manipulation leads to buffer overflow. The attack may be initiated remotely. The exploit is publicly available and might be used.

  • 7.7 High severity

    Cisco Secure Firewall Adaptive Security…: Buffer Copy without Checking Size of Input

    CVE-2026-20100Cisco

    A vulnerability in the LUA interperter of the Remote Access SSL VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN con

  • 8.8 High severity

    LLM-Claw: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CVE-2025-12345LLM-Claw

    A security vulnerability has been detected in LLM-Claw 0.1.0/0.1.1/0.1.1a/0.1.1a-p1. The affected element is the function agent_deploy_init of the file /agents/deploy/initiate.c of the component Agent Deployment. Such manipulation leads to buffer overflow. It

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24112Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the value of `userInfo`. When `userInfo` is passed into the `addWewifiWhiteUser` function and processed by `sscanf` without size validation, it could

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24110Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may send overly long `addDhcpRules` data. When these rules enter the `addDhcpRule` function and are processed by `ret = sscanf(pRule, " %d\t%[^\t]\t%[^\n\r\t]", &dhcpsIndex, dhcpsIP, dhcpsMac);

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24115Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Failure to validate the sizes of `gstup` and `gstdwn` before concatenating them into `gstruleQos` may lead to buffer overflow.

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24113Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by controlling the value of `nptr`. When this value is passed into the `getMibPrefix` function and concatenated using `sprintf` without proper size validation, it

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24111Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the value of `userInfo`. When `userInfo` is passed into the `addAuthUser` function and processed by `sscanf` without size validation, it could lead t

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24109Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by controlling the value of `picName`. When this value is used in `sprintf` without validating variable sizes, it could lead to a buffer overflow vulnerability.

  • 9.8 Critical severity

    W20e Firmware: Buffer Copy without Checking Size of Input

    CVE-2026-24108Tenda

    An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by controlling the value of `nptr`. When this value is passed into the `getMibPrefix` function and concatenated using `sprintf` without proper size validation, it