CVE-2021-22563Public exploit

Crash or memory disclosure via undersized spline cache

Published Nov 1, 2021 · Updated Sep 17, 2024

Out-of-bounds read in Google libjxl 0.6.0 and earlier allows local users to crash decoders or disclose memory via a crafted image. ProcessDCGlobal initializes the spline draw cache with unpadded frame dimensions, so DrawSegments can index segment_y_start beyond its allocated rows when larger upsampled coordinates are used. Triggering the flaw requires decoding an invalid JPEG XL image containing splines; consequences are a crash or unintended pixels derived from process memory.

CVSS severity4.5
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Google libjxl 0.6.0 and earlier allows local users to crash decoders or disclose memory via a crafted image. ProcessDCGlobal initializes the spline draw cache with unpadded frame dimensions, so DrawSegments can index segment_y_start beyond its allocated rows when larger upsampled coordinates are used. Triggering the flaw requires decoding an invalid JPEG XL image containing splines; consequences are a crash or unintended pixels derived from process memory.

The record

CVE
CVE-2021-22563
Published
Nov 1, 2021
Updated
Sep 17, 2024
Vendor
Go standard library
Product
libjxl
Classifications
CWE-126
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=0.6.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Go standard library · libjxlversion=unspecified <=0.6.0

Published CVSS scores

4.5Google LLCCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-126Buffer Over-read

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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