CVE-2022-27046Public exploitNetwork attack vector

Process crash via dangling dither reference

Published Apr 8, 2022 · Updated Aug 3, 2024

Heap use-after-free in libsixel 1.8.6 allows context-dependent attackers to crash img2sixel via a crafted GIF image. During GIF conversion, sixel_encoder_prepare_palette frees the dither context, but sixel_encoder_encode_frame later passes the dangling reference to sixel_dither_unref, which reads its reference count. The demonstrated path requires img2sixel to process attacker-supplied image content and terminates the instrumented process; no code execution was demonstrated.

CVSS severity8.8
High
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap use-after-free in libsixel 1.8.6 allows context-dependent attackers to crash img2sixel via a crafted GIF image. During GIF conversion, sixel_encoder_prepare_palette frees the dither context, but sixel_encoder_encode_frame later passes the dangling reference to sixel_dither_unref, which reads its reference count. The demonstrated path requires img2sixel to process attacker-supplied image content and terminates the instrumented process; no code execution was demonstrated.

The record

CVE
CVE-2022-27046
Published
Apr 8, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

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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