CVE-2026-40469

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.

The gawk package is the GNU implementation of awk. The awk utility interprets a special-purpose programming language that makes it possible to handle simple data-reformatting jobs with just a few lines of code.

Security Fix(es):

Use After Free vulnerability has been found in "io.c" program file of gawk (do_getline_redir() routine). This issue may lead to a crash. It affects gawk in versions 5.4.0 and below.(CVE-2026-40467)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk. This issue may lead to memory exhaustion on the hosting operating system and could be used to overwrite gawk heap metadata and objects with attacker-controlled bytes. It affects gawk in versions 5.4.0 and below.(CVE-2026-40468)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.(CVE-2026-40469)

Buffer overflow vulnerability has been found in "extension/readdir.c" program file of gawk (ftype() routine). This issue could be used to crash the program and potentially to achieve code execution, although the latter has not been confirmed to be feasible. It affects gawk in versions 5.4.0 and below.(CVE-2026-40553)

The gawk package is the GNU implementation of awk. The awk utility interprets a special-purpose programming language that makes it possible to handle simple data-reformatting jobs with just a few lines of code.

Security Fix(es):

Use After Free vulnerability has been found in "io.c" program file of gawk (do_getline_redir() routine). This issue may lead to a crash. It affects gawk in versions 5.4.0 and below.(CVE-2026-40467)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk. This issue may lead to memory exhaustion on the hosting operating system and could be used to overwrite gawk heap metadata and objects with attacker-controlled bytes. It affects gawk in versions 5.4.0 and below.(CVE-2026-40468)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.(CVE-2026-40469)

Buffer overflow vulnerability has been found in "extension/readdir.c" program file of gawk (ftype() routine). This issue could be used to crash the program and potentially to achieve code execution, although the latter has not been confirmed to be feasible. It affects gawk in versions 5.4.0 and below.(CVE-2026-40553)

The gawk package is the GNU implementation of awk. The awk utility interprets a special-purpose programming language that makes it possible to handle simple data-reformatting jobs with just a few lines of code.

Security Fix(es):

Use After Free vulnerability has been found in "io.c" program file of gawk (do_getline_redir() routine). This issue may lead to a crash. It affects gawk in versions 5.4.0 and below.(CVE-2026-40467)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk. This issue may lead to memory exhaustion on the hosting operating system and could be used to overwrite gawk heap metadata and objects with attacker-controlled bytes. It affects gawk in versions 5.4.0 and below.(CVE-2026-40468)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.(CVE-2026-40469)

Buffer overflow vulnerability has been found in "extension/readdir.c" program file of gawk (ftype() routine). This issue could be used to crash the program and potentially to achieve code execution, although the latter has not been confirmed to be feasible. It affects gawk in versions 5.4.0 and below.(CVE-2026-40553)

Integer overflow vulnerability has been found in "builtin.c" program file of gawk (do_sub() routine). This issue could be used to overwrite gawk heap metadata and objects causing the program to crash. It affects 32-bit builds of gawk in versions 5.4.0 and below.

• CVE-2026-40467: fix use-after-free in do_getline_redir() in io.c (redir_exp dereferenced after being freed)
• CVE-2026-40553: fix stack buffer overflow in ftype() in the readdir extension (unbounded path concatenation before stat())
• CVE-2026-40469: fix integer overflow in do_sub() in builtin.c (64-bit overflow check on the result-buffer size prevents heap corruption in sub/gsub/gensub replacement expansion on 32-bit builds)

• CVE-2026-40467: fix use-after-free in do_getline_redir() in io.c (redir_exp dereferenced after being freed)
• CVE-2026-40553: fix stack buffer overflow in ftype() in the readdir extension (unbounded path concatenation before stat())
• CVE-2026-40469: fix integer overflow in do_sub() in builtin.c (64-bit overflow check on the result-buffer size prevents heap corruption in sub/gsub/gensub replacement expansion on 32-bit builds)

• Fix CVE-2026-40469: integer overflow in substitution result buffer sizing

• CVE-2026-40467: fix use-after-free in do_getline_redir() in io.c (redir_exp dereferenced after being freed)
• CVE-2026-40553: fix stack buffer overflow in ftype() in the readdir extension (unbounded path concatenation before stat())
• CVE-2026-40469: fix integer overflow in do_sub() in builtin.c (64-bit overflow check on the result-buffer size prevents heap corruption in sub/gsub/gensub replacement expansion on 32-bit builds)

• Fix CVE-2026-40469: integer overflow in substitution result buffer sizing

• Fix CVE-2026-40469: integer overflow in substitution result buffer sizing

• CVE-2023-4156: builtin.c (format_tree): when collecting positional field widths or precisions, check for wrap around to negative values
• CVE-2026-40469: builtin.c (sub_common): check for overflow in the result buffer size calculation using 64-bit math, failing with a fatal error instead of corrupting the heap on 32-bit builds

• CVE-2023-4156: builtin.c (format_tree): when collecting positional field widths or precisions, check for wrap around to negative values
• CVE-2026-40469: builtin.c (sub_common): check for overflow in the result buffer size calculation using 64-bit math, failing with a fatal error instead of corrupting the heap on 32-bit builds

Use after free in gawk. (CVE-2026-40467) Heap buffer overflow in gawk. (CVE-2026-40468) Heap buffer overflow in gawk. (CVE-2026-40469) Stack-based buffer overflow in gawk. (CVE-2026-40553)

It was discovered that Gawk incorrectly handled memory when processing input using the getline redirection. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-40467)

It was discovered that Gawk incorrectly handled certain integer calculations when allocating memory. An attacker could possibly use this issue to cause a denial of service or overwrite heap memory with attacker-controlled data. (CVE-2026-40468)

It was discovered that Gawk incorrectly handled certain integer calculations when performing substitutions. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-40469)

It was discovered that Gawk incorrectly handled memory when reading directory entries. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-40553)