A code execution flaw was found in Emacs, affecting versions prior to 31.2. The Flymake mode using language backends other than Lisp would execute arbitrary code from the edited file while performing syntax checking. Viewing or editing untrusted files using Emacs could lead to arbitrary code execution with the privileges of the user running Emacs.

A flaw was found in GNU patch. An attacker can achieve arbitrary file creation outside the intended working directory by enticing a user or automated workflow to apply a specially crafted patch file. Due to missing validation during automatic patch reversal, absolute file paths in patch headers are accepted rather than rejected. Consequently, the utility can create files in arbitrary locations with the permissions of the executing user.

Jakub Wilk found that a2ps, a tool to convert text and other types of files to PostScript, insecurely used a temporary file in spyuser(). A local attacker could use this flaw to perform a symbolic link attack to modify an arbitrary file accessible to the user running a2ps.

The original report in the Debian bug tracking system (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=737385) notes the issue is in src/main.c:

559 tempnameensure (job->tmpfilenames[0]); 560 spyname = job->tmpfilenames[0]; 561 spy = fopen (spyname, "w");

And also notes there are other calls to tempnameensure().

GNU Emacs could provide weaker than expected security, caused by an issue with contents of remote files to be trusted in Org mode. A remote attacker could exploit this vulnerability to launch further attacks on the system.

GNU Emacs could allow a remote attacker to execute arbitrary code on the system, caused by a code injection flaw in org-link-expand-abbrev in lisp/ol.el. By sending a specially crafted request, an attacker could exploit this vulnerability to execute arbitrary code on the system.

An issue was discovered in GNU Emacs through 28.2. htmlfontify.el has a command injection vulnerability. In the hfy-istext-command function, the parameter file and parameter srcdir come from external input, and parameters are not escaped. If a file name or directory name contains shell metacharacters, code may be executed.

The ftp client in GNU Inetutils before 2.2 does not validate addresses returned by PASV/LSPV responses to make sure they match the server address. This is similar to CVE-2020-8284 for curl.

Buffer overflow in digest calculation function of multiple RADIUS implementations allows remote attackers to cause a denial of service and possibly execute arbitrary code via shared secret data.

Multiple RADIUS implementations do not properly validate the Vendor-Length of the Vendor-Specific attribute, which allows remote attackers to cause a denial of service (crash) via a Vendor-Length that is less than 2.

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 2.43 or earlier, may result in an attempt to read bytes before an allocated buffer, potentially resulting in unintentional disclosure of neighboring data in the heap, or a program crash.

Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.

Last updated 30 June 2026

Buffer overread in nsprintrrf with corrupted RDATA field

A flaw was found in libstdc++. An integer overflow can occur when processing large inputs to the aligned operator new in the C++ library. This vulnerability could lead to an undersized memory allocation, potentially causing memory corruption or application instability.

Stack overflow in nscd due to unbounded alloca use

A time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges. When expanding $ORIGIN in DTRPATH for setuid/setgid (ATSECURE) programs, glibc validates the lexically normalized search path against the trusted directories but then opens the raw, un-normalized path. On systems where the Linux fs.protectedhardlinks sysctl is disabled, a local attacker who hard-links such a program into an attacker-controlled directory and wins a race to replace an intermediate path component with a symbolic link can direct the loader outside the trusted directory, causing it to load an attacker-controlled shared object and execute arbitrary code with the elevated privileges of the program.

Exploitation requires an installed setuid or setgid binary whose DTRPATH uses $ORIGIN followed by ".." traversal that normalizes into a trusted directory, and the ability to hard-link that binary and win the race by swapping a path component for a symbolic link. Major Linux-based OS distributions ship with fs.protectedhardlinks enabled by default and mitigate the vulnerability.

A stack-based buffer overflow in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to crash or corrupt the memory of setuid/setgid (ATSECURE) programs.

When such a program's DTRPATH or DTRUNPATH begins with $ORIGIN and is followed by NUL or '/' the loader both reads past the end of the path buffer and writes past the end of a stack-allocated internal buffer. The corrupted loader stack can lead to a loader crash (denial of service) and limited disclosure of process memory.

Initializing the DNS stub resolver from an /etc/resolv.conf file, or a LOCALDOMAIN environment variable, whose search list contains a domain of roughly 200 characters or more in the GNU C Library version 2.26 to 2.44 results in an assertion failure which aborts the process.

The resolver truncates the search list when copying it into the fixed-size res.defdname buffer, then asserts that the copy is consistent with the full configuration. The consistency check compared against the wrong size and did not handle a first entry that does not fit, so a correctly truncated list failed the assertion. Any process that resolves names through the library is affected, including long-running processes that reload /etc/resolv.conf on the next query after it changes. Search domains are commonly written to /etc/resolv.conf from data received over DHCP or from a VPN server, so an attacker on the local network may be able to trigger this without privileges on the target system, subject to validation by the network configuration software.

The nscd service in the GNU C Library 2.3.4 onwards may crash due to a stack overflow when a malicious DNS server returns too large a response for a DNS query, resulting in degraded DNS resolution for the system.

Exploitation of this bug needs a system that has nscd enabled and using an untrusted DNS server for name resolution, with the compromised DNS server being capable of processing records large enough to result in a stack overflow in an nscd thread stack. During experimentation, bind 9 was unable to handle large records, but that could change in future or with a different name server. In typical installations, nscd is executed in an isolated context as its own user without a shell, due to which any compromise of that service is isolated.

There is a remote possibility of nscd cache corruption if an attacker manages to get the stack pointer into a desired point in the heap, potentially resulting in other caches in nscd being overwritten with corrupt data through the stack overflow, until the buggy code path eventually results in a crash.

Finally, a crash in nscd may result in performance degradation when resolving names, but it does not result in a denial of service.

A stack-based buffer overflow in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to crash or corrupt the memory of setuid/setgid (ATSECURE) programs.

When such a program's DTRPATH or DTRUNPATH begins with $ORIGIN and is followed by NUL or '/' the loader both reads past the end of the path buffer and writes past the end of a stack-allocated internal buffer. The corrupted loader stack can lead to a loader crash (denial of service) and limited disclosure of process memory.

A time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges. When expanding $ORIGIN in DTRPATH for setuid/setgid (ATSECURE) programs, glibc validates the lexically normalized search path against the trusted directories but then opens the raw, un-normalized path. On systems where the Linux fs.protectedhardlinks sysctl is disabled, a local attacker who hard-links such a program into an attacker-controlled directory and wins a race to replace an intermediate path component with a symbolic link can direct the loader outside the trusted directory, causing it to load an attacker-controlled shared object and execute arbitrary code with the elevated privileges of the program.

Exploitation requires an installed setuid or setgid binary whose DTRPATH uses $ORIGIN followed by ".." traversal that normalizes into a trusted directory, and the ability to hard-link that binary and win the race by swapping a path component for a symbolic link. Major Linux-based OS distributions ship with fs.protectedhardlinks enabled by default and mitigate the vulnerability.

An integer overflow triggered when processing inputs to the C++ new operator in libstdc+-v3/libsupc+/newopa.cc where sz + align could overflow with large sz or align, potentially resulting in an undersized allocation instead of throwing badalloc. Note that this only affects older gcc versions since 12.4 onwards (see pr113258) prefer posixmemalign over alignedalloc so on the RHEL front this should only affect RHEL9 and RHEL8 system gcc. The older libstdc++ (8.5.0) has a slightly different variant of that expression but has the same overflow problem.

A vulnerability has been found in GNU LibreDWG up to 0.13.4. The affected element is the function dwgbmp of the file src/dwg.c of the component BMP Image Handler. Such manipulation leads to heap-based buffer overflow. The attack must be carried out locally. The exploit has been disclosed to the public and may be used. Upgrading to version 0.14 is sufficient to fix this issue. The name of the patch is 18fd542bb4d5ccedf9de12052bf50068b2b26f06. It is suggested to upgrade the affected component.

GNU Emacs < 31.0.91 Heap Over-Read via PBM/PPM/PGM Image Loader

GNU Emacs before 31.0.91 contains an integer overflow in the PBM/PPM/PGM image loader that allows an attacker to leak heap memory contents by supplying a crafted image with large dimensions and an elevated max color index. The image loader multiplies image dimensions and channel count using signed integer arithmetic; for sufficiently large values, the result wraps to a negative number, bypassing the bounds check and causing the pixel reader to access heap memory past the end of the allocated buffer. The over-read contents are interpreted as pixel color values and rendered on screen.

GNU Emacs for Android is vulnerable to an integer overflow in the sfntreadcmapformat12() function in src/sfnt.c. When processing a crafted TrueType font file, an unguarded addition in the xmalloc allocation call wraps around on 32-bit builds, causing a heap buffer overflow write. An attacker can deliver a malicious font file via email, EWW (Emacs Web Wowser), or documents with custom faces, causing Emacs to load it. This results in heap memory corruption that can lead to code execution.

This issue was fixed in commit c4e20777c26548722a37b03db93243e83a0d6188

Arbitrary Command Execution in GNU Bison

Arbitrary Output Location Change in GNU Bison

A buffer overflow can occur when calculating the quantile value using the Statistics Library of GSL (GNU Scientific Library), versions 2.5 and 2.6. Processing a maliciously crafted input data for gslstatsquantilefromsorteddata of the library may lead to unexpected application termination or arbitrary code execution.

guix-daemon in GNU Guix before 5ab3c4c allows privilege escalation because build outputs are accessible by local users before file metadata concerns (e.g., for setuid and setgid programs) are properly addressed. The vulnerability can be remediated within the product via certain pull, reconfigure, and restart actions. Both 5ab3c4c and 5582241 are needed to resolve the vulnerability.