01 Record

CVE-2025-40928

JSON::XS before version 4.04 for Perl has an integer buffer overflow causing a segfault when parsing crafted JSON, enabling denial-of-service attacks or other unspecified impact

HighPUBLISHEDCNA: CPANSec

CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

View raw JSON

02 Description

JSON::XS before version 4.04 for Perl has an integer buffer overflow causing a segfault when parsing crafted JSON, enabling denial-of-service attacks or other unspecified impact

03 Exploitation and scoring

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.67% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 51.8% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Deferred. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2025-09-08 15:08Z1 YR AGO

Last updated

2025-11-04 21:10Z11 MO AGO

Reserved

2025-04-16

Assigning CNA

CPANSec

Record state

PUBLISHED

Severity

High (CVSS 7.5)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

CWE-122Heap-based Buffer OverflowVariant

Data version

5.2

Document digest

b0976788e97e4419a3df6d6656ed077cdf94efd4025a112feb28209e4737dac6

05 Affected products

VendorProductVersionsPlatforms

MLEHMANNJSON::XS0 to < 4.04—

06 References

metacpan.orghttps://metacpan.org/release/MLEHMANN/JSON-XS-4.03/source/XS.xs#L256related
security.metacpan.orghttps://security.metacpan.org/patches/J/JSON-XS/4.03/CVE-2025-40928-r1.patchpatch
lists.debian.orghttps://lists.debian.org/debian-lts-announce/2025/09/msg00033.html
www.openwall.comhttp://www.openwall.com/lists/oss-security/2025/09/08/2

07 Remediation

Update to 4.04, or apply the provided patch

08 Fixed in

AlmaLinux 8

perl-JSON-XS
Fixed in 1:3.04-4.el8_10

AlmaLinux 9

perl-JSON-XS
Fixed in 1:4.04-1.el9_6

AlmaLinux 10

perl-JSON-XS
Fixed in 1:4.04-1.el10_0

CloudLinux 8

perl-JSON-XS
Fixed in 1:3.04-4.el8_10

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

CloudLinux 9

perl-JSON-XS
Fixed in 1:4.04-1.el9_6

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

CloudLinux 10

perl-JSON-XS
Fixed in 1:4.04-1.el10_0

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Debian 12

libjson-xs-perl
Fixed in 4.040-1~deb12u1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

libjson-xs-perl
Fixed in 4.040-1~deb13u1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

libjson-xs-perl
Fixed in 4.030-3

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.