CVE-2024-56406 | Perl is vulnerable to a heap buffer overflow when transliterating non-ASCII bytes

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.

Published: 2025-04-13 Last update: 2026-06-17 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e

Conclusion & alert: CVE-2024-56406 is rated Moderate Risk (47/100): CVSS High severity, with low exploitation likelihood (EPSS 0.47%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-56406

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.47% +0.41%
2 2026-02-04 0.02% 0.06% +0.04%
3 2026-02-01 0.02%

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-56406

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.4 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.5 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-56406

OS Trackers for CVE-2024-56406

vendor priority summary link
alpine CVE-2024-56406: 1 source package rows (perl); 26 state rows across 6 repos (3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 18. https://security.alpinelinux.org/vuln/CVE-2024-56406
debian unimportant CVE-2024-56406 unimportant priority: Debian including 1 source packages (perl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2024-56406
redhat high https://access.redhat.com/security/cve/CVE-2024-56406
suse high CVE-2024-56406 severity important: SUSE including 259 source package names (13.2-9.1:perl-5.38.2-slfo.1.1_2.1, 13.2-9.1:perl-base-5.38.2-slfo.1.1_2.1, …), 449 product×package rows across 86 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (86 product lines)): Known Affected 231, Known Not Affected 130, Fixed 88. https://www.suse.com/security/cve/CVE-2024-56406/
ubuntu medium CVE-2024-56406 medium priority: Ubuntu including 1 source packages (perl), 9 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, trusty, upstream, xenial): released 5, not-affected 4. https://ubuntu.com/security/CVE-2024-56406

Affected software / configurations for CVE-2024-56406

Vendor Product Version Raw CPE
perl perl >= 5.33.1, < 5.38.4 cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*
perl perl >= 5.39.0, < 5.40.2 cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*
perl perl >= 5.41.0, <= 5.41.10 cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*

References for CVE-2024-56406

cvelogic Threat Intelligence