CVE Feed

    Dashboard / CVE / CVE-2026-4438

    CVE-2026-4438

    Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.

    Published:Mar 20, 2026
    Last Modified:Apr 8, 2026
    EPS:Mar 20, 2026
    EPSS Score:0.00026
    CVSS Score:5.4

    Affected Products

    Vendor
    Gnu
    Product
    Glibc
    Vendor
    The Gnu C Library
    Product
    Glibc

    Exploits

    https://sourceware.org/bugzilla/show_bug.cgi?id=34015

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-10 Buffer Overflow via Environment Variables
    CAPEC-101 Server Side Include (SSI) Injection
    CAPEC-104 Cross Zone Scripting
    CAPEC-108 Command Line Execution through SQL Injection
    CAPEC-109 Object Relational Mapping Injection
    CAPEC-110 SQL Injection through SOAP Parameter Tampering
    CAPEC-120 Double Encoding
    CAPEC-13 Subverting Environment Variable Values
    CAPEC-135 Format String Injection
    CAPEC-136 LDAP Injection
    CAPEC-137 Parameter Injection
    CAPEC-14 Client-side Injection-induced Buffer Overflow
    CAPEC-153 Input Data Manipulation
    CAPEC-174 Flash Parameter Injection
    CAPEC-182 Flash Injection
    CAPEC-209 XSS Using MIME Type Mismatch
    CAPEC-22 Exploiting Trust in Client
    CAPEC-23 File Content Injection
    CAPEC-230 Serialized Data with Nested Payloads
    CAPEC-231 Oversized Serialized Data Payloads
    CAPEC-24 Filter Failure through Buffer Overflow
    CAPEC-250 XML Injection
    CAPEC-261 Fuzzing for garnering other adjacent user/sensitive data
    CAPEC-267 Leverage Alternate Encoding
    CAPEC-28 Fuzzing
    CAPEC-3 Using Leading 'Ghost' Character Sequences to Bypass Input Filters
    CAPEC-31 Accessing/Intercepting/Modifying HTTP Cookies
    CAPEC-41 Using Meta-characters in E-mail Headers to Inject Malicious Payloads
    CAPEC-42 MIME Conversion
    CAPEC-43 Exploiting Multiple Input Interpretation Layers
    CAPEC-45 Buffer Overflow via Symbolic Links
    CAPEC-46 Overflow Variables and Tags
    CAPEC-460 HTTP Parameter Pollution (HPP)
    CAPEC-468 Generic Cross-Browser Cross-Domain Theft
    CAPEC-47 Buffer Overflow via Parameter Expansion
    CAPEC-473 Signature Spoof
    CAPEC-52 Embedding NULL Bytes
    CAPEC-53 Postfix, Null Terminate, and Backslash
    CAPEC-588 DOM-Based XSS
    CAPEC-63 Cross-Site Scripting (XSS)
    CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic
    CAPEC-664 Server Side Request Forgery
    CAPEC-67 String Format Overflow in syslog()
    CAPEC-7 Blind SQL Injection
    CAPEC-71 Using Unicode Encoding to Bypass Validation Logic
    CAPEC-72 URL Encoding
    CAPEC-73 User-Controlled Filename
    CAPEC-78 Using Escaped Slashes in Alternate Encoding
    CAPEC-79 Using Slashes in Alternate Encoding
    CAPEC-8 Buffer Overflow in an API Call
    CAPEC-80 Using UTF-8 Encoding to Bypass Validation Logic
    CAPEC-81 Web Server Logs Tampering
    CAPEC-83 XPath Injection
    CAPEC-85 AJAX Footprinting
    CAPEC-88 OS Command Injection
    CAPEC-9 Buffer Overflow in Local Command-Line Utilities

    Related CVEs

    CVE-2026-80489 (CVSS 5.9) — A flaw was found in glibc. This vulnerability allows a remote attacker to cause a denial of service (DoS) by p…
    CVE-2026-77117 (CVSS 5.9) — A flaw was found in glibc. A remote attacker could exploit this vulnerability by providing specially crafted i…
    CVE-2026-19499 (CVSS 6.8) — A flaw was found in glibc. The strfmon and strfmon_l functions are vulnerable to a buffer overflow when proces…
    CVE-2026-19542 (CVSS 4.2) — A flaw was found in glibc. An out-of-bounds array write vulnerability exists within the `tdelete` function. Th…
    CVE-2026-6368 (CVSS 2.1) — Calling wordexp with WRDE_APPEND in the GNU C Library version 2.0 to version 2.43 can cause the interface to r…
    CVE-2026-6238 (CVSS 6.5) — The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.0.1 to version 2…
    CVE-2026-5435 (CVSS 7.3) — The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.2 and newer fail…
    CVE-2026-5450 (CVSS 9.8) — Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 t…
    CVE-2026-5928 (CVSS 7.5) — Calling the ungetwc function on a FILE stream with wide characters encoded in a character set that has overlap…
    CVE-2026-4046 (CVSS 7.5) — The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when…

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High