How severe is CVE-2020-21050?

CVE-2020-21050 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-21050 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-21050?

CVE-2020-21050 affects Saitoha Libsixel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-21050?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-21050 published?

CVE-2020-21050 was published on 2021-09-14 and last updated on 2026-06-17.

CVE-2020-21050

CVE-2020-21050 is a medium-severity vulnerability in Saitoha Libsixel with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Saitoha Libsixel
Published: 2021-09-14
Last modified: 2026-06-17

Description

Libsixel prior to v1.8.3 contains a stack buffer overflow in the function gif_process_raster at fromgif.c.

Frequently asked questions

What is CVE-2020-21050?: Libsixel prior to v1.8.3 contains a stack buffer overflow in the function gif_process_raster at fromgif.c.
How severe is CVE-2020-21050?: CVE-2020-21050 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-21050 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-21050?: CVE-2020-21050 affects Saitoha Libsixel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-21050?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-21050 published?: CVE-2020-21050 was published on 2021-09-14 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:saitoha:libsixel:*:*:*:*:*:*:*:*

More vulnerabilities in Saitoha Libsixel

CVE-2019-19638 — Critical (CVSS 9.8): An issue was discovered in libsixel 1.8.2. There is a heap-based buffer overflow in the function load_pnm at frompnm.c,…
CVE-2019-19637 — Critical (CVSS 9.8): An issue was discovered in libsixel 1.8.2. There is an integer overflow in the function sixel_decode_raw_impl at…
CVE-2019-19636 — Critical (CVSS 9.8): An issue was discovered in libsixel 1.8.2. There is an integer overflow in the function sixel_encode_body at tosixel.c.
CVE-2019-19635 — Critical (CVSS 9.8): An issue was discovered in libsixel 1.8.2. There is a heap-based buffer overflow in the function sixel_decode_raw_impl…
CVE-2022-27046 — High (CVSS 8.8): libsixel 1.8.6 suffers from a Heap Use After Free vulnerability in in libsixel/src/dither.c:388.
CVE-2022-27044 — High (CVSS 8.8): libsixel 1.8.6 is affected by Buffer Overflow in libsixel/src/quant.c:876.

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