CWE-127 (Buffer Under-read) documents a weakness type used across vulnerability databases and security assessments. Use the sections below for definition, context, and mapped CVEs.
The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations prior to the targeted buffer.
| Kind | Name | Class | Prevalence | OS / CPE |
|---|---|---|---|---|
| language | — | Memory-Unsafe | Undetermined | — |
| language | C | — | Undetermined | — |
| language | C++ | — | Undetermined | — |
These CVEs are mapped to this weakness in this database and kept for traceability and search.
| CVE | Published | Summary |
|---|---|---|
| CVE-2026-45683 | 2026-06-02 | OpenTelemetry eBPF Instrumentation provides eBPF instrumentation based on the OpenTelemetry standard. Prior to version 0.9.0, the Java TLS ioctl probe reads user-controlled ioctl pointers with bpf_pro… |
| CVE-2026-5928 | 2026-04-20 | Calling the ungetwc function on a FILE stream with wide characters encoded in a character set that has overlaps between its single byte and multi-byte character encodings, in the GNU C Library version… |
| CVE-2025-20359 | 2025-10-15 | Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder that could allow an unauthenticated, remote attacker to cause the disclosure of possible sensitive data or cause the… |
| CVE-2025-32050 | 2025-04-03 | A flaw was found in libsoup. The libsoup append_param_quoted() function may contain an overflow bug resulting in a buffer under-read. |
| CVE-2024-10395 | 2025-02-03 | No proper validation of the length of user input in http_server_get_content_type_from_extension. |
| CVE-2024-25629 | 2024-02-23 | c-ares is a C library for asynchronous DNS requests. `ares__read_line()` is used to parse local configuration files such as `/etc/resolv.conf`, `/etc/nsswitch.conf`, the `HOSTALIASES` file, and if usi… |
| CVE-2020-1918 | 2021-03-10 | In-memory file operations (ie: using fopen on a data URI) did not properly restrict negative seeking, allowing for the reading of memory prior to the in-memory buffer. This issue affects HHVM versions… |
| CVE-2020-5360 | 2020-12-16 | Dell BSAFE Micro Edition Suite, versions prior to 4.5, are vulnerable to a Buffer Under-Read Vulnerability. An unauthenticated remote attacker could potentially exploit this vulnerability resulting in… |
| Date | Name | Version | Importance | Comment |
|---|---|---|---|---|
| 2008-09-08 | CWE Content Team | 1.0 | — | updated Applicable_Platforms, Relationships, Taxonomy_Mappings, Weakness_Ordinalities |
| 2009-10-29 | CWE Content Team | 1.6 | — | updated Description, Relationships |
| 2011-06-01 | CWE Content Team | 1.13 | — | updated Common_Consequences |
| 2012-05-11 | CWE Content Team | 2.2 | — | updated Relationships |
| 2014-07-30 | CWE Content Team | 2.8 | — | updated Relationships, Taxonomy_Mappings |
| 2017-11-08 | CWE Content Team | 3.0 | — | updated Causal_Nature |
| 2019-09-19 | CWE Content Team | 3.4 | — | updated Common_Consequences, References |
| 2020-02-24 | CWE Content Team | 4.0 | — | updated Relationships |
| 2023-01-31 | CWE Content Team | 4.10 | — | updated Description |
| 2023-04-27 | CWE Content Team | 4.11 | — | updated References, Relationships |
| 2023-06-29 | CWE Content Team | 4.12 | — | updated Mapping_Notes |
| 2023-10-26 | CWE Content Team | 4.13 | — | updated Observed_Examples |
| 2025-09-09 | CWE Content Team | 4.18 | — | updated Affected_Resources, Common_Consequences, Demonstrative_Examples, Functional_Areas |
| 2025-12-11 | CWE Content Team | 4.19 | — | updated Applicable_Platforms, Description, Detection_Factors, Modes_of_Introduction, References |