How severe is CVE-2020-21049?

CVE-2020-21049 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-2020-21049 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-21049?

CVE-2020-21049 affects Saitoha Libsixel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-21049?

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

When was CVE-2020-21049 published?

CVE-2020-21049 was published on 2021-09-14 and last updated on 2026-06-17.

CVE-2020-21049

CVE-2020-21049 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-125.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Saitoha Libsixel
Published: 2021-09-14
Last modified: 2026-06-17

Description

An invalid read in the stb_image.h component of libsixel prior to v1.8.5 allows attackers to cause a denial of service (DOS) via a crafted PSD file.

Frequently asked questions

What is CVE-2020-21049?: An invalid read in the stb_image.h component of libsixel prior to v1.8.5 allows attackers to cause a denial of service (DOS) via a crafted PSD file.
How severe is CVE-2020-21049?: CVE-2020-21049 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-2020-21049 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-21049?: CVE-2020-21049 affects Saitoha Libsixel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-21049?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-21049 published?: CVE-2020-21049 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.

All CVEs affecting Saitoha Libsixel →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →