CVE-2021-22564 | Out of bounds Copy in Libjxl in large image groups

Exp

For certain valid JPEG XL images with a size slightly larger than an integer number of groups (256x256 pixels) when processing the groups out of order the decoder can perform an out of bounds copy of image pixels from an image buffer in the heap to another. This copy can occur when processing the right or bottom edges of the image, but only when groups are processed in certain order. Groups can be processed out of order in multi-threaded decoding environments with heavy thread load but also with images that contain the groups in an arbitrary order in the file. It is recommended to upgrade past 0.6.0 or patch with https://github.com/libjxl/libjxl/pull/775

Published: 2021-11-01 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-22564 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.30%). 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-2021-22564

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

Exploit prediction scoring system (EPSS) score for CVE-2021-22564

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 0.04% 0.30% +0.26%
2 2025-03-17 0.06% 0.04% -0.02%
3 2023-05-25 — 0.06% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22564

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L 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: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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.0 3.4 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/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: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: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]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-22564

OS Trackers for CVE-2021-22564

vendor priority summary link
debian unimportant CVE-2021-22564 unimportant priority: Debian including 1 source packages (jpeg-xl), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2021-22564

Affected software / configurations for CVE-2021-22564

Vendor Product Version Raw CPE
libjxl_project libjxl <= 0.6.0 cpe:2.3:a:libjxl_project:libjxl:*:*:*:*:*:*:*:*

References for CVE-2021-22564

URL Tags
https://github.com/libjxl/libjxl/issues/708 Exploit Issue Tracking Third Party Advisory
https://github.com/libjxl/libjxl/pull/775 Patch Third Party Advisory
cvelogic Threat Intelligence