CVE-2026-46521 | ImageMagick: Heap Buffer Over-Write in MIFF encoder when using LZMA compression

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 6.9.13-48 and 7.1.2-23, when using LZMA compression in the MIFF encoder an out of bounds write can occur due to a missing check. This issue has been patched in versions 6.9.13-48 and 7.1.2-23.

Published: 2026-06-10 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-46521 is rated Low Risk (23.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.15%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2026-46521

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 0.01% 0.15% +0.14%
2 2026-06-11 0.01%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-46521

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-46521

GitHub Security Advisory for CVE-2026-46521

GHSA-jcqp-6r6f-3mfx · Severity: medium · Ecosystem: nuget — ImageMagick: Heap Buffer Over-Write in MIFF encoder when using LZMA compression

OS Trackers for CVE-2026-46521

vendor priority summary link
debian not yet assigned CVE-2026-46521 not yet assigned priority: Debian including 1 source packages (imagemagick), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-46521
redhat medium https://access.redhat.com/security/cve/CVE-2026-46521
suse medium https://www.suse.com/security/cve/CVE-2026-46521/
ubuntu medium CVE-2026-46521 medium priority: Ubuntu including 1 source packages (imagemagick), 9 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 9. https://ubuntu.com/security/CVE-2026-46521

Affected software / configurations for CVE-2026-46521

Vendor Product Version Raw CPE
imagemagick imagemagick < 6.9.13-48 cpe:2.3:a:imagemagick:imagemagick:*:*:*:*:*:*:*:*
imagemagick imagemagick >= 7.0.0-0, < 7.1.2-23 cpe:2.3:a:imagemagick:imagemagick:*:*:*:*:*:*:*:*

References for CVE-2026-46521

cvelogic Threat Intelligence