Perl: Security Vulnerabilities
Perl versions through 5.43.10 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack.
S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves with a signed length comparison that passes when the length is negative, advancing the buffer pointer out of bounds.
A template derived from untrusted input can read heap memory past the buffer and return it to the caller.
CVSS Score
8.4
EPSS Score
0.002
Published
2026-07-13
Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk.
When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error.
A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.
CVSS Score
9.1
EPSS Score
0.006
Published
2026-07-13
DBI versions before 1.650 for Perl have a heap overflow when preparsing SQL statements with an extreme number of placeholders.
The fix for CVE-2026-10879 did not allocate enough memory to handle approximately 1.2-million placeholders.
DBI version 1.650 sets a hard limit of 99,999 placeholders.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-07-07
DBI versions before 1.650 for Perl read one byte out-of-bounds in preparse when deleting an initial SQL comment.
The preparse method normalises SQL and removes comments. When the SQL starts with a comment line, the deletion of that line during normalisation led to an out-of-bounds read by one byte. The result is a fault on memory-hardened builds and nondeterministic newline retention on normal builds.
CVSS Score
9.1
EPSS Score
0.004
Published
2026-07-07
DBI versions before 1.650 for Perl are vulnerable to code injection via caller-influenced Profile.
When a string is assigned to a DBI handle's Profile attribute, DBI splits it into path, package and arguments, and interpolates the package part in a string eval with no validation of the package name.
Any caller-influenced value that reaches the Profile attribute is therefore arbitrary Perl code execution, including calls to run system commands.
The Profile attribute can be set from three different sources that can carry untrusted data: the DBI_PROFILE environment variable, a direct attribute assignment, and a DSN driver-attribute clause dbi:Driver(Profile=>SPEC):db.
An attacker controlling any of those inputs runs arbitrary Perl in the host process. The strongest remote position is a network-exposed DBI::Gofer / DBI::ProxyServer whose per-request DSN reaches the Profile attribute, letting a client execute code on the broker host.
CVSS Score
8.8
EPSS Score
0.005
Published
2026-07-07
DBI versions before 1.648 for Perl saved errors in a limited-sized buffer.
Error messages that were returned when RaiseError, PrintError or HandleError were set were written to a 200-byte buffer without a length limit.
Attackers that can influence the error text in an application can trigger a buffer overflow.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-06-09
DBI versions before 1.648 for Perl have a heap overflow when preparsing SQL statements with more than 9 binders.
The preparse method expands SQL placeholder characters to numbered binders of the form :pN, but only allocates three characters per binder in the buffer. Placeholders 10-99 require four characters, 100-999 require five characters, et cetera.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-06-05
Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds.
Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer.
A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-05-26
Perl versions from 5.9.4 before 5.40.4-RC1, from 5.41.0 before 5.42.2-RC1, from 5.43.0 before 5.43.9 contain a vulnerable version of Compress::Raw::Zlib.
Compress::Raw::Zlib is included in the Perl package as a dual-life core module, and is vulnerable to CVE-2026-3381 due to a vendored version of zlib which has several vulnerabilities, including CVE-2026-27171. The bundled Compress::Raw::Zlib was updated to version 2.221 in Perl blead commit c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94.
CVSS Score
9.8
EPSS Score
0.007
Published
2026-03-29
A heap buffer overflow vulnerability was discovered in Perl.
Release branches 5.34, 5.36, 5.38 and 5.40 are affected, including development versions from 5.33.1 through 5.41.10.
When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`.
$ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;'
Segmentation fault (core dumped)
It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.
CVSS Score
8.4
EPSS Score
0.005
Published
2025-04-13
Page 1