CVE-2024-6874 | macidn punycode buffer overread

Exp

libcurl's URL API function [curl_url_get()](https://curl.se/libcurl/c/curl_url_get.html) offers punycode conversions, to and from IDN. Asking to convert a name that is exactly 256 bytes, libcurl ends up reading outside of a stack based buffer when built to use the *macidn* IDN backend. The conversion function then fills up the provided buffer exactly - but does not null terminate the string. This flaw can lead to stack contents accidently getting returned as part of the converted string.

Published: 2024-07-24 Last update: 2026-06-17 Assigner: 2499f714-1537-4658-8207-48ae4bb9eae9 Source: 2499f714-1537-4658-8207-48ae4bb9eae9
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-6874 is rated Exploit Available (50/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.79%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2024-6874

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2024-6874

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 0.99% 0.79% -0.20%
2 2026-03-04 0.41% 0.99% +0.58%
3 2026-03-01 — 0.41% —

Full EPSS history (33 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-6874

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]
3.1 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-6874

OS Trackers for CVE-2024-6874

vendor priority summary link
alpine low CVE-2024-6874: 1 source package rows (curl); 214 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 207. https://security.alpinelinux.org/vuln/CVE-2024-6874
debian unimportant CVE-2024-6874 unimportant priority: Debian including 1 source packages (curl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2024-6874
redhat low — https://access.redhat.com/security/cve/CVE-2024-6874
suse medium CVE-2024-6874 severity moderate: SUSE including 52 source package names (0.0.17-1.1:curl-8.14.1-150600.4.28.1, 0.0.17-1.1:libcurl4-8.14.1-150600.4.28.1, …), 288 product×package rows across 119 product lines (Container bci/spack, Container containers/lmcache-lmstack-router, … (119 product lines)): Fixed 179, Known Not Affected 109. https://www.suse.com/security/cve/CVE-2024-6874/
ubuntu low CVE-2024-6874 low priority: Ubuntu including 1 source packages (curl), 8 status rows across 8 suites (bionic, focal, jammy, noble, oracular, trusty, upstream, xenial): not-affected 7, needs-triage 1. https://ubuntu.com/security/CVE-2024-6874

Affected software / configurations for CVE-2024-6874

Vendor Product Version Raw CPE
haxx libcurl 8.8.0 cpe:2.3:a:haxx:libcurl:8.8.0:*:*:*:*:*:*:*

References for CVE-2024-6874

cvelogic Threat Intelligence