CVE-2021-46700
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in...
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
CVE-2021-46700- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-415
- Updated
- 2026-11-02
CVE List No score
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
CVE-2021-46700- Updated
- 2026-11-02
EUVDEUVD-2021-33360 No score
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
EUVD-2021-33360- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-5mpg-37cw-j7g5
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in...
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
GHSA-5mpg-37cw-j7g5- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-415
- Updated
- 2026-11-02
OSV
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
CVE-2021-46700- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-46700
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
DEBIAN-CVE-2021-46700- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-46700
In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.
- Record
UBUNTU-CVE-2021-46700- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libsixelDebian:12 |
All versions, plus listed versions 1.10.3-31.10.5-11:1.8.7-11:1.8.7-21:1.8.7-3 Show 4 moreShow less1:1.8.7-41:1.8.7-51:1.8.7-61:1.8.7-r2-1 |
None known |
libsixelDebian:13 |
All versions, plus listed versions 1.10.5-11:1.8.7-11:1.8.7-21:1.8.7-31:1.8.7-41:1.8.7-51:1.8.7-61:1.8.7-r2-1 |
None known |
libsixelDebian:14 |
All versions, plus listed versions 1.10.5-11:1.8.7-11:1.8.7-21:1.8.7-31:1.8.7-41:1.8.7-51:1.8.7-61:1.8.7-r2-1 |
None known |
libsixelUbuntu:16.04:LTS |
All versions, plus listed versions 1.4.2-11.5.2-2 |
None known |
libsixelUbuntu:18.04:LTS |
All versions, plus listed versions 1.5.2-21.7.3-1 |
None known |
libsixelUbuntu:20.04:LTS |
All versions, plus listed versions 1.8.2-11.8.2-2.1 |
None known |
libsixelUbuntu:22.04:LTS |
All versions, plus listed versions 1.8.6-21.10.3-21.10.3-3 |
None known |
libsixelUbuntu:24.04:LTS |
All versions, plus listed versions 1.10.3-31.10.3-3build1 |
None known |
libsixelUbuntu:25.10 |
All versions, plus listed versions 1.10.5-1 |
None known |
libsixelUbuntu:26.10 |
All versions, plus listed versions 1.10.5-1build11:1.8.7-r2-1 |
None known |
libsixelUbuntu:26.04:LTS |
All versions, plus listed versions 1.10.5-11.10.5-1build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-46700 is a medium vulnerability (CVSS 6.5) in Saitoha Libsixel, published February 19, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.95%, the 61st percentile. No source names a fixed version.