CVE-2026-19499
HighCVSS 7.7Exploitation Probability (EPSS)
Low risk32th percentile - higher than 32% of all known CVEs
Summary
In GNU C Library versions 2.38 to 2.44, calling strfmon or strfmon_l can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding. Exploitation requires an application code path that calls these functions with right-justified width padding into a destination buffer large enough for the padding but too small for the internal memmove call. At the time of publication, no network-facing application impact is known.
Risk Assessment
The vulnerability may lead to memory corruption in applications using strfmon or strfmon_l with a specific formatting pattern, potentially enabling code execution or a crash. The risk is limited to applications that call these functions in a susceptible way.
Recommendation
Update GNU C Library to a version containing the fix, or avoid calling strfmon/strfmon_l with right-justified width padding. Review application code for such calls.
Other vulnerabilities in GNU C Library
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The iconv() function in the GNU C Library versions 2.39 and older may overflow the output buffer by up to 4 bytes when converting strings to the ISO-2022-CN-EXT character set. This may lead to application crashes or overwrite a neighbouring variable.
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In GNU C Library versions 2.27 to 2.38, an untrusted LD_LIBRARY_PATH environment variable vulnerability allows attacker-controlled loading of dynamically shared libraries in statically compiled setuid binaries that call dlopen (including internal dlopen calls after setlocale or calls to NSS functions).
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A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.
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An exploitable signed comparison vulnerability exists in the ARMv7 memcpy() implementation of GNU glibc 2.30.9000. Calling memcpy() with a negative value for the 'num' parameter results in a signed comparison vulnerability, potentially leading to out-of-bounds memory writes and remote code execution.
- CVE-2018-19591High
In the GNU C Library (glibc) through version 2.28, attempting to resolve a crafted hostname via getaddrinfo() leads to the allocation of a socket descriptor that is not closed. This is related to the if_nametoindex() function.
- CVE-2026-84243High
A vulnerability in the GNU C Library (glibc) version 2.0 and later affects the gettext family of functions, which accept LANGUAGE environment variable entries containing '/' or equal to '..'. This allows an attacker to load a crafted message catalog (.mo file) from an arbitrary filesystem location, potentially crashing the program or executing arbitrary code with the program's privileges. The flaw is not covered by the earlier CVE-2014-0475 fix, which addressed other environment variables.
- CVE-2026-97399Low
The strncasecmp function in the GNU C Library 2.24 and later optimized for the Power8 architecture may read one byte beyond the input size limit, which may crash a program when that byte is not readable. This occurs when attacker-controlled input strings match up to the edge of their page and the neighboring page is either not mapped or not readable.
Original NVD description (English source)
Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding. Exploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller. At the time of publication, no network-facing application impact is known.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

