Passing an effectively empty string to the ,ccs= syntax extension of the mode argument in the fopen function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled.
This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for ccs should not pass them through without validation.
The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.2 and newer fail to validate the RDATA content against the RDATA length in a DNS response when processing LOC, CERT, TKEY or TSIG records, which may allow an attacker to craft a DNS response, causing a target application to crash or read uninitialized memory.
These functions are for application debugging only and hence not in the path of code executed by the DNS resolver. Further, they have been deprecated since version 2.34 and should not be used by any new applications. Applications should consider porting away from these interfaces since they may be removed in future versions.
Hello,
The following security advisory has been published:
GLIBC-SA-2026-0015: ===================
Passing an effectively empty string to the ,ccs= syntax extension of the mode argument in the fopen function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled.
This usage pattern is not seen in applications in common GNU or Linux distributions and applications that process user-supplied values for ccs should not pass them through without validation.
CVE-Id: CVE-2026-18374 Public-Date: 2026-08-27 Vulnerable-Commit: 129d706d77587e4d6627cc1ebef9be0f7cbc65f0 Reported-by: AISLE in partnership with Red Hat CVSS: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L - 4.9
Notes: ======
Published advisories are available directly in the project git repository: https://sourceware.org/git/?p=glibc.git;a=tree;f=advisories;hb=HEAD
Calling gethostbyaddr or gethostbyaddrr 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.
The "Security related changes" section below lists fixes for CVE-2026-4046, CVE-2026-4437, & CVE-2026-4438.
-------- Forwarded Message -------- Subject: The GNU C Library version 2.44 is now available Date: Sat, 25 Jul 2026 18:49:56 +0900 From: Andreas K. Huettel <dilfridge () gentoo org> Organization: Gentoo Linux To: libc-alpha () sourceware org, libc-announce () sourceware org, info-gnu () gnu org
The GNU C Library =================
The GNU C Library version 2.44 is now available.
The GNU C Library is used as the C library in the GNU system and in GNU/Linux systems, as well as many other systems that use Linux as the kernel.
The GNU C Library is primarily designed to be a portable and high performance C library. It follows all relevant standards including ISO C23 and POSIX.1-2024. It is also internationalized and has one of the most complete internationalization interfaces known. The GNU C Library website is at http://www.gnu.org/software/libc/
Packages for the 2.44 release may be downloaded from: http://ftpmirror.gnu.org/libc/ http://ftp.gnu.org/gnu/libc/
The mirror list is at http://www.gnu.org/order/ftp.html
Distributions are encouraged to track the release/ branches corresponding to the releases they are using. The release branches will be updated with conservative bug fixes and new features while retaining backwards compatibility.
NEWS for version 2.44 =====================
Major new features:
System-wide tunables can be applied using /etc/tunables.conf and running ldconfig. Specific tunable settings and the /etc/tunables.conf file format and path are not part of the stable library interfaces and may change between releases.
A new tunable, glibc.elf.thp, is added to map read-only segments with Transparent Huge Pages (THP) if THP is not disabled in the kernel. When glibc.elf.thp is set to 1, malloc uses the actual kernel THP mode instead of defaulting to madvise mode and madvisethp will stop issuing MADVHUGEPAGE if kernel THP mode is always.
The THP page size in malloc is capped to MAXTHPPAGESIZE. If the THP page size is above MAXTHPPAGESIZE, THP in malloc is disabled.
Additional optimized and correctly rounded mathematical functions have been imported from the CORE-MATH project, in particular cosh, sinh, and tanh.
Many additional improvements to existing functions have been synchronized from the CORE-MATH project.
For C++26, the assert macro is now variadic, allowing more complex arguments containing commas (which however still must evaluate to a single value).
The SVID error handling for cosh and sinh was moved to compatibility symbols, allowing improvements in performance.
Static PIE is now supported for arm--linux-gnueabi. It requires toolchain support to correctly set the expected linker options.
On AArch64 targets that support the Guarded Control Stack extension all GCS operations (including status, write on shadow stack, and push to shadow stack) are locked after enabling GCS with ENFORCED or OVERRIDE GCS policy. When a GCS operation is locked, a program cannot change this operation status via the prctl syscall. This prevents disabling or corrupting the GCS shadow stack during runtime.
On AArch64 targets, log, exp, sin, cas, sinh, cosh, asinh, acosh, atanh single and double precision special cases have been vectorized for SVE and AdvSIMD, and vector variants of powr have been added.
On RISC-V targets, vector extension optimized variants of memcmp, memccpy, memchr, memcpy, memmove, stpncpy, strcmp, strchr, strcpy, strncmp, strncpy, strlen, and strrchr have been added.
On PowerPC, memchr optimized for Power10 has been re-added.
Support for LoongArch32 has been added.
Pre-built ld.so.cache files can be installed with ldconfig.
A new locale has been added: hrxBR (Hunsrik language spoken in Brazil).
Deprecated and removed features, and other changes affecting compatibility:
Although malloc and related functions currently return pointers aligned to alignof (maxalignt), the documentation now says future versions of glibc may relax alignment requirements for small allocations. For example, a future malloc(1) might return a pointer with odd alignment, because no object of size 1 can have a fundamental alignment greater than 1.
The s390-linux-gnu (31bit) configuration is no longer supported.
The --enable-memory-tagging configure option has been removed. The corresponding AArch64-specific functionality that was previously activated by this flag has been removed as well.
The --enable-static-nss configure option has been removed. It had no effect on the build since the NSS reorganization in glibc 2.33; its only remaining behavior was to suppress the link-time warnings on the NSS interface functions in libc.a, which are now emitted unconditionally.
Security related changes:
The following CVEs were fixed in this release, details of which can be found in the advisories directory of the release tarball:
GLIBC-SA-2026-0005: gethostbyaddr and gethostbyaddrr may incorrectly handle DNS response (CVE-2026-4437)
GLIBC-SA-2026-0006: gethostbyaddr and gethostbyaddrr return invalid DNS hostnames (CVE-2026-4438)
GLIBC-SA-2026-0007: iconv crash due to assertion failure with untrusted input (CVE-2026-4046)
The following bugs were resolved with this release:
[2363] libc: EOPNOTSUPP and ENOTSUP in errno.h must be different, according to SUSv3 [3794] manual: iconv: //TRANSLIT and //IGNORE feature not documented [15792] dynamic-link: [arm] ARM dynamic linker should save/restore coprocessor registers [20331] libc: fts ignores errors from readdir() [20680] dynamic-link: ifunc resolver cannot access the thread pointer with static linking [22944] libc: fts cannot traverse paths which have a length longer than USHRTMAX [25257] libc: sotruss: fix error message for '--f' argument [25770] locale: newlocale memory leak in LOCPATH parsing and on error paths [27582] libc: x8664: IFUNC in static user programs may crash when built with -fstack-protector-all [28218] dynamic-link: ld.so: ifunc resolver calls a lazy PLT. When does it work? [28817] libc: static-pie ifunc resolver tls failure [28940] nss: nssdatabaseget doesn't check for allocation failure [30136] manual: Please document behaviour of iconv(3) when input is untranslatable [30304] nptl: nptl/tst-pthread-gdb-attach test fails with new libc shared library version [30769] malloc: malloctrim is not working correctly for arenas other than arena 0 [30976] dynamic-link: rtld: resolve ifunc relocations after JUMPSLOT/GLOBDAT/etc [30992] libc: alpha: setrlimit() with negative values besides RLIMINFINITY returns EPERM [31901] libc: elf/tst-glibc-hwcaps-prepend-cache fails on i686 [33226] math: math-vector-fortran.h vs not ffast-math [33626] libc: execvpe should skip inaccessible $PATH components [33650] build: abilist.awk doesn't handle unversioned defined symbols [33785] stdio: New streams are linked into global list before they are fully initialized [33848] build: Build fails at openat2.h, redefinition of 'struct openhow' [33882] libc: Recursion in nftw() causes stack overflow(CWE-674) [33904] build: error: 'vasprintfchk' undeclared here [33921] build: Building with Linux-7.0-rc1 errors on OPENTREECLONE [33935] stdio: IOwfiledoallocate not linked correctly when linking glibc statically [33980] locale: iconv: ibm139x trigger assertion error when converting to internal while lack enough room (CVE-2026-4046) [33985] build: ld: cannot find -lgccs: No such file or directory [33999] stdio: libio: potential dangling IOsavebase or memory leak in wgenops.c [34006] stdio: libio: inconsistent fmemopenwrite behavior on last \0 [34008] stdio: stdio-common: scanf %mc pattern will cause heap overflow when width > 1024 [34014] nss: gethostbyaddr and gethostbyaddrr may incorrectly handle DNS response [34015] nss: gethostbyaddr and gethostbyaddrr return invalid DNS hostnames [34019] stdio: libio: undefined behavior when setbuf on openmemstream [34033] network: resolv/nsprint.c: nssprintrrf TSIG path bypasses buflen and can overflow caller buffer [34064] dynamic-link: The unnecessary PTNOTE check in when loading a binary [34069] network: Buffer overread in nssprintrrf with corrupted RDATA field (CVE-2026-6238) [34070] hurd: Calling open ("/dev/tty/", ORDONLY) causes the program to segfault [34073] regex: regexec can mistakenly match with backrefs and the $ anchor [34079] dynamic-link: THP segment load aligns all PTLOAD segments to THP page size [34080] dynamic-link: Support THP segment load with THP enabled with madvise [34083] dynamic-link: getthpmode and getthpsize are called twice [34090] libc: wordexp WRDEAPPEND rollback restores stale wewordv, leading to invalid free in wordfree [34098] libc: Missing SUPPORTSTATICPIE in arm32 [34129] string: x86: Non-temporal memset unreachable on AMD Zen 3/4/5 [34144] libc: ld.so clobbers VFP registers during runtime linking [34154] network: Segfault in sockeq after resinit() returns -1, due to stale u.ext.nscount in resiclose [34156] dynamic-link: dlsym(RTLDDEFAULT, ...) from a constructor SIGSEGVs when tail-called [34164] dynamic-link: elf: IFUNC resolvers do not see static TLS initialization [34170] dynamic-link: elf: IFUNC resolver reading global- dynamic/TLSDESC thread variable crashes inside tlsgetaddr [34183] math: fma produces wrong results [34192] nptl: pthreadsetnamenp opens /proc/<tid>/comm with ORDWR instead of OWRONLY|OCLOEXEC [34196] libc: elf: static dlopen: pointer guard of the loaded ld.so/libc.so is left uninitialized [34197] dynamic-link: elf: Stack canary and pointer guard are recoverable from ATRANDOM (getauxval) [34205] libc: aarch64: SIGSEGV in tunablestrcmp in static-pie binaries run with a string tunable [34208] stdio: scanf not pushback after matching failure [34210] libc: elf/tst-glibc-hwcaps-prepend-cache fails on armv7a-unknown-linux-gnueabihf [34236] locale: Non-representable transliteration still causes iconv to exit with 1 if //TRANSLIT is specified [34289] network: nssprintrrf uses pclass, ptype internally [34311] build: THP tests failed to link [34347] libc: Incorrect trailing bitfield word of struct tcpinfo [34348] dynamic-link: FAIL: elf/tst-thp-1 if THP is disabled in kernel [34351] build: Random test failures [34355] build: [2.44 Regression] "make check -j7 subdirs=stdio-common" no longer works [34396] libc: sparc64-unknown-linux-gnu , Gentoo: >200 test failures, SIGILL in many binaries [34398] string: Truncated strncpy on s390x z900 ifunc variant
Release Notes =============
https://sourceware.org/glibc/wiki/Release/2.44
Contributors ============
This release was made possible by the contributions of many people. The maintainers are grateful to everyone who has contributed changes or bug reports. These include:
Adam Yi Adhemerval Zanella Alejandro Colomar Andreas K. Hüttel Andreas Schwab Arjun Shankar Aurelien Jarno Avinal Kumar Brian Jorgensen Carlos O'Donell Carlos Peón Costa Charlotte Mcmenamin Collin Funk Cosmina Dunca DJ Delorie Daan De Meyer Deng Jianbo Dev Jain Diego Nieto Cid Dmitry Kovalenko Dylan Fleming Etienne Brateau Fabian Rast Florian Weimer Frédéric Bérat Garccez George Hu H.J. Lu Jakub Jelinek Jiamei Xie Jiho Lee Jiri Stransky John David Anglin Jonathan Wakely Josef Johansson Joseph Myers Justus Winter Luca Boccassi Lucas Chollet Martin Coufal Matt Turner Michael Ford Michael Jeanson Michael Kelly Mike FABIAN Mike Kelly Muhammad Kamran Nicolas Boulenguez Paul Eggert Peter Bergner Peter Collingbourne Petr Menšík Pierre Blanchard Pino Toscano Pádraig Brady Richard Wild Rocket Ma RyotaSaito Sachin Monga Sajan Karumanchi Sam James Samuel Balazi Samuel Thibault Sana Kazi Sergey Kolosov Shamil Abdulaev Shengwen Cheng Siddhesh Poyarekar Stefan Liebler Thomas Daubney Tomasz Kamiński Uros Bizjak WANG Rui Weihong Ye Weixie Cui Wilco Dijkstra Xi Ruoyao Xiang Gao Yao Zihong Yunze Zhu Yury Khrustalev Zihong Yao mengqinggang xiejiamei zombie12138
We would like to call out the following and thank them for their tireless patch review:
Adhemerval Zanella Andreas K. Hüttel Arjun Shankar Aurelien Jarno caiyinyu Carlos O'Donell Collin Funk DJ Delorie Florian Weimer Frédéric Bérat Ganesh Gopalasubramanian H.J. Lu JiangNing Mathieu Desnoyers Paul Eggert Paul Zimmermann Peter Bergner Sam James Samuel Thibault Siddhesh Poyarekar Stefan Liebler Sunil K Pandey Wilco Dijkstra Yury Khrustalev
-- PD Dr. Andreas K. Hüttel dilfridge () gentoo org Gentoo Linux developer (council, comrel, toolchain, base-system, perl, libreoffice) https://wiki.gentoo.org/wiki/User:Dilfridge
Hello,
The following security advisory has been published:
GLIBC-SA-2026-0007: ===================
iconv crash due to assertion failure with untrusted input
The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when converting inputs from the IBM1390 or IBM1399 character sets, which may be used to remotely crash an application.
This vulnerability can be trivially mitigated by removing the IBM1390 and IBM1399 character sets from systems that do not need them.
Notes: ======
Published advisories are available directly in the project git repository: https://sourceware.org/git/?p=glibc.git;a=tree;f=advisories;hb=HEAD