Off-by-one Error
CWE-193
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
We track 79 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.0. 1 has been exploited in real attacks.
How this weakness is prevented
- Implementation: When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array. Some examples of functions susceptible to this weakness in C include strcpy(), strncpy(), strcat(), strncat(), printf(), sprintf(), scanf() and sscanf().
Latest Off-by-one Error vulnerabilities
- 8.8 High severity
Chrome: Off-by-one Error
Off-by-one error in V8 in Google Chrome prior to 157.0.8103.78 allowed a remote attacker to potentially execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
- 7.0 High severity
FFmpeg: Off-by-one Error
FFmpeg through 9.0.2 contains an off-by-one heap overflow vulnerability in get_exponent_dynamic() in libavcodec/nellymoserenc.c that allows writing one element past the opt and path allocations. Attackers can supply crafted audio to applications encoding Nelly
- 7.5 High severity
psqlODBC: Stack-based Buffer Overflow
The psqlODBC parser for ODBC escape sequences in application SQL text writes the argument offsets of a {fn} escape into a fixed 16-entry stack array without a bound and does not initialize the array. An escape with too many arguments overflows the stack, and a
- 7.1 High severity
Ntfs-3g: Heap-based Buffer Overflow
In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_decompress() in compress.c that allows an attacker to corrupt one byte of heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by reading the
- 8.8 High severity
wolfSSH: Stack-based Buffer Overflow
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
- 7.3 High severity
A vulnerability was detected in Trusted Domain Project OpenDMARC up to 1.4.2.
A vulnerability was detected in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this vulnerability is the function opendmarc_util_cleanup in the library libopendmarc/opendmarc_util.c of the component DMARC Record Parser. Performing a manipulation res
- 7.3 High severity
A vulnerability was detected in Trusted Domain Project OpenDKIM up to 2.11.0.
A vulnerability was detected in Trusted Domain Project OpenDKIM up to 2.11.0. Affected is the function dkim_qp_decode of the file util.c of the component Decoder. The manipulation results in off-by-one. The attack may be performed from remote. The exploit is n
- 8.1 High severity
A vulnerability was identified in D-Link DIR-605 B1v202WWB03.
A vulnerability was identified in D-Link DIR-605 B1v202WWB03. This issue affects the function tunnel_set_params of the file progs.gpl/pppd.alpha/l2tp/tunnel.c of the component L2TP Control Message Parser. Such manipulation of the argument peer_hostname leads t
- 7.5 High severity
core-rs-albatross: Off-by-one Error
Nimiq is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Through 1.5.0, the validity store uses a strict lower-bound comparison that expires a stored transaction too early relative to Transaction::is_valid
- 7.5 High severity
Apache Tomcat: Off-by-one Error
Off-by-one Error vulnerability in Apache Tomcat impacting the [N] flag on the rewrite valves causes rewrite processing to restart at the second rule rather than the first rule. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 th
- 9.1 Critical severity
Chrome: Off-by-one Error
Off-by-one error in DevTools in Google Chrome prior to 152.0.7977.65 allowed a remote attacker leveraging social engineering to potentially read memory inside the sandbox via a crafted Chrome extension. (Chromium security severity: Low)
- 7.0 High severity
libevent: Stack-based Buffer Overflow
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an off-by-one stack buffer overflow in evdns.c when dnsname_to_labels formats a name-bearing DNS record at the end of the 64 KB stack buffer allocated by evdns_server_requ
- 7.1 High severity
FreeRDP: Out-of-bounds Read
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use
- 7.5 High severity
OpenVPN: Stack-based Buffer Overflow
OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response from a malicious proxy server
- 7.5 High severity
Thunderbird: Off-by-one Error
The code to parse MIME headers for display when forwarding a message (if the setting to view all headers was enabled) had an off-by-one error, allowing a single byte to be read from the memory after the buffer for the headers, and potentially crashing Thunderb
- 9.8 Critical severity
Linux: Off-by-one Error
In the Linux kernel, the following vulnerability has been resolved: net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring When an sk_msg scatterlist ring wraps (sg.end < sg.start), tls_push_record() chains the tail portion of the ring to the
- 7.8 High severity
Red Hat Enterprise Linux 8: Off-by-one Error
A flaw was found in GIMP's PNM file format parser. When parsing a specially crafted PNM file, the pnmscanner_gettoken() function writes a null terminator one byte past the end of a stack-allocated buffer due to an off-by-one error in the loop boundary check. T
- 7.5 High severity
libreswan: Off-by-one Error
An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a
- 7.6 High severity
UltraVNC: Off-by-one Error
UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer _dn[2024]
- 7.1 High severity
hostapd: Off-by-one Error
In hostapd before 2.12, a missing bounds check in AP-mode Wi-Fi 7 (IEEE 802.11be) Multi-Link Operation (MLO) association request processing allows an unauthenticated attacker within wireless range to send a crafted management frame containing a malformed Multi
- 8.6 High severity
GLib: Off-by-one Error
A flaw was found in GLib. An off-by-one error can occur in the g_key_file_get_locale_string_list function in the gkeyfile.c file when loading a key file with an empty value. This flaw can cause an out-of-bounds access of 1 byte or a denial of service when the
- 9.8 Critical severity
Linux: Off-by-one Error
In the Linux kernel, the following vulnerability has been resolved: ocfs2/dlm: fix off-by-one in dlm_match_regions() region comparison The local-vs-remote region comparison loop uses '<=' instead of '<', causing it to read one entry past the valid range of qr_
- 7.3 High severity
canboat: Off-by-one Error
CANBoat through 6.22, fixed in commit a5a22b7, contains an off-by-one global buffer overflow in the searchForPgn() function in analyzer/pgn.c that allows remote attackers to crash the application. Attackers can deliver a crafted NMEA-2000 message with an out-o
- 7.5 High severity
RTKLIB: Off-by-one Error
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fi
- 9.8 Critical severity
Linux: Off-by-one Error
In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: fix off-by-one in bcmgenet_put_txcb The write_ptr points to the next open tx_cb. We want to return the tx_cb that gets rewinded, so we must rewind the pointer first then return
- 7.8 High severity
Linux: Off-by-one Error
In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix off-by-one in check_imm signed range check check_imm(bits, imm) is used in the arm64 BPF JIT to verify that a branch displacement (in arm64 instruction units) fits into the sig
- 7.8 High severity
LibreOffice: Off-by-one Error
LibreOffice Calc compiles cell formulas when opening a spreadsheet. A heap buffer overflow existed when compiling a very long formula made up of many opening tokens. The array that tracks nesting depth was allocated one element too small for that worst case, s
- 8.6 High severity
nanoMODBUS: Off-by-one Error
nanoMODBUS through v1.23.0 contains an off-by-one buffer overflow in the recv_msg_header function of the Modbus/TCP server that allows remote unauthenticated attackers to write one attacker-controlled byte past the end of the 260-byte receive buffer by sending
- 7.8 High severity
Linux: Off-by-one Error
In the Linux kernel, the following vulnerability has been resolved: media: rockchip: rkcif: fix off by one bugs Change these comparisons from > vs >= to avoid accessing one element beyond the end of the arrays. While at it, use ARRAY_SIZE instead of the _MAX e
- 8.6 High severity
MPD: Off-by-one Error
Music Player Daemon (MPD) before version 0.24.11 contains a stack buffer overflow vulnerability in the pcm_unpack_24be function in src/pcm/Pack.cxx that allows unauthenticated attackers to corrupt stack memory by triggering an off-by-one write in the PCM decod
- 9.8 Critical severity
Fastnetmon: Out-of-bounds Write
FastNetMon Community Edition through 1.2.9 contains an off-by-one heap-based buffer overflow in the dynamic_binary_buffer_t class (src/dynamic_binary_buffer.hpp). Five methods (append_dynamic_buffer, append_data_as_pointer, append_data_as_object_ptr, memcpy_fr
- 7.5 High severity
Postfix: Off-by-one Error
Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number.
- 7.5 High severity
bacnet-stack: Out-of-bounds Read
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an off-by-one out-of-bounds read vulnerability in bacnet-stack's ReadPropertyMultiple service decoder allows unauthenticated remote attackers to read one byte p
- 7.1 High severity
Red Hat Enterprise Linux 10: Off-by-one Error
A flaw was found in GNU Emacs. This vulnerability, a memory corruption issue, occurs when Emacs processes specially crafted SVG (Scalable Vector Graphics) CSS (Cascading Style Sheets) data. A local user could exploit this by convincing a victim to open a malic
- 7.5 High severity
core-rs-albatross: Out-of-bounds Read
nimiq/core-rs-albatross is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.3.0, an untrusted peer could crash a validator by publishing a signed tendermint proposal message where signer
- 8.1 High severity
moby: Off-by-one Error
Moby is an open source container framework. Prior to version 29.3.1, a security vulnerability has been detected that allows plugins privilege validation to be bypassed during docker plugin install. Due to an error in the daemon's privilege comparison logic, th
- 7.8 High severity
everest-core: Off-by-one Error
EVerest is an EV charging software stack. Prior to version 2026.02.0, an off-by-one check in IsoMux certificate filename handling causes a stack-based buffer overflow when a filename length equals `MAX_FILE_NAME_LENGTH` (100). A crafted filename in the certifi
- 7.1 High severity
Red Hat Enterprise Linux 7 Extended Lifecycle…: Off-by-one Error
A flaw was found in GIMP. This issue is a heap buffer over-read in GIMP PCX file loader due to an off-by-one error. A remote attacker could exploit this by convincing a user to open a specially crafted PCX image. Successful exploitation could lead to out-of-bo
- 7.8 High severity
fontconfig: Off-by-one Error
fontconfig before 2.17.1 has an off-by-one error in allocation during sfnt capability handling, leading to a one-byte out-of-bounds write, and potentially a crash or code execution. This is in FcFontCapabilities in fcfreetype.c.
- 8.4 High severity
arduino-TuyaOpen: Off-by-one Error
arduino-TuyaOpen before version 1.2.1 contains a single-byte buffer overflow vulnerability in the WiFiMulti component. When the victim's smart hardware connects to an attacker-controlled AP hotspot, the attacker can exploit the overflow to execute arbitrary co