CVE-2021-46700

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2022-02-20. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
55%
KEV
Not listed

Published

February 19, 2022

Last Modified

April 24, 2026

References (2)

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
libsixel1.10.3-1 ... 1:1.8.7-r2-1 (12 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
libsixel1.10.3-3 ... 1:1.8.7-r2-1 (9 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
libsixel1.10.5-1 ... 1:1.8.7-r2-1 (8 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libsixel1.10.5-1 ... 1:1.8.7-r2-1 (8 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 6× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 183 total refreshes for this CVE.

  1. 2026-09-07 15:58 UTCEPSS rescore
  2. 2026-09-06 13:45 UTCEPSS rescore
  3. 2026-09-05 15:25 UTCEPSS rescore
  4. 2026-09-04 13:57 UTCEPSS rescore
  5. 2026-09-04 05:03 UTCEPSS rescore
  6. 2026-09-02 14:09 UTCEPSS rescore
  7. 2026-09-01 13:51 UTCEPSS rescore
  8. 2026-08-30 19:14 UTCEPSS rescore
  9. 2026-08-30 02:43 UTCOSV refresh
  10. 2026-08-30 01:19 UTCEPSS rescore
  11. 2026-08-28 21:38 UTCEPSS rescore
  12. 2026-08-27 14:22 UTCEPSS rescore
  13. 2026-08-26 14:43 UTCEPSS rescore
  14. 2026-08-25 13:46 UTCEPSS rescore
  15. 2026-08-24 14:13 UTCEPSS rescore
  16. 2026-08-21 23:46 UTCEPSS rescore
  17. 2026-08-20 22:52 UTCEPSS rescore
  18. 2026-08-19 17:01 UTCEPSS rescore
  19. 2026-08-18 13:45 UTCEPSS rescore
  20. 2026-08-17 13:44 UTCEPSS rescore
  21. 2026-08-16 14:53 UTCEPSS rescore
  22. 2026-08-16 02:11 UTCEPSS rescore
  23. 2026-08-15 01:27 UTCEPSS rescore
  24. 2026-08-13 21:57 UTCEPSS rescore
  25. 2026-08-13 13:21 UTCOSV refresh
Show 75 more
  1. 2026-08-12 13:48 UTCEPSS rescore
  2. 2026-08-11 13:38 UTCEPSS rescore
  3. 2026-08-09 13:44 UTCEPSS rescore
  4. 2026-08-08 16:34 UTCEPSS rescore
  5. 2026-08-07 16:24 UTCEPSS rescore
  6. 2026-08-06 13:44 UTCEPSS rescore
  7. 2026-08-05 19:15 UTCEPSS rescore
  8. 2026-08-04 15:06 UTCEPSS rescore
  9. 2026-08-04 10:34 UTCEPSS rescore
  10. 2026-08-03 10:33 UTCEPSS rescore
  11. 2026-08-02 02:24 UTCEPSS rescore
  12. 2026-08-01 04:13 UTCEPSS rescore
  13. 2026-07-30 16:25 UTCEPSS rescore
  14. 2026-07-30 01:28 UTCEPSS rescore
  15. 2026-07-28 20:47 UTCOSV refresh
  16. 2026-07-28 15:33 UTCEPSS rescore
  17. 2026-07-26 14:52 UTCEPSS rescore
  18. 2026-07-25 14:15 UTCEPSS rescore
  19. 2026-07-24 14:15 UTCEPSS rescore
  20. 2026-07-24 14:15 UTCEPSS rescore
  21. 2026-07-23 14:16 UTCEPSS rescore
  22. 2026-07-23 02:06 UTCEG score recompute
  23. 2026-07-22 22:52 UTCEG score recompute
  24. 2026-07-22 14:06 UTCEPSS rescore
  25. 2026-07-21 15:22 UTCEPSS rescore
  26. 2026-07-21 15:22 UTCEPSS rescore
  27. 2026-07-20 17:05 UTCEPSS rescore
  28. 2026-07-19 14:29 UTCEPSS rescore
  29. 2026-07-19 02:27 UTCEPSS rescore
  30. 2026-07-19 02:27 UTCEPSS rescore
  31. 2026-07-18 10:02 UTCEPSS rescore
  32. 2026-07-16 17:00 UTCEPSS rescore
  33. 2026-07-16 17:00 UTCEPSS rescore
  34. 2026-07-15 16:55 UTCEPSS rescore
  35. 2026-07-15 01:58 UTCEPSS rescore
  36. 2026-07-15 01:58 UTCEPSS rescore
  37. 2026-07-13 22:27 UTCEPSS rescore
  38. 2026-07-12 05:44 UTCEPSS rescore
  39. 2026-07-11 13:11 UTCOSV refresh
  40. 2026-07-11 08:25 UTCEPSS rescore
  41. 2026-07-09 19:07 UTCEPSS rescore
  42. 2026-07-09 19:07 UTCEPSS rescore
  43. 2026-07-08 15:12 UTCEPSS rescore
  44. 2026-07-08 15:12 UTCEPSS rescore
  45. 2026-07-07 13:43 UTCEPSS rescore
  46. 2026-07-06 16:25 UTCEPSS rescore
  47. 2026-07-06 16:25 UTCEPSS rescore
  48. 2026-07-06 02:21 UTCEPSS rescore
  49. 2026-07-06 02:21 UTCEPSS rescore
  50. 2026-07-05 02:28 UTCEPSS rescore
  51. 2026-07-05 02:28 UTCEPSS rescore
  52. 2026-07-04 06:29 UTCEPSS rescore
  53. 2026-07-04 06:29 UTCEPSS rescore
  54. 2026-07-01 15:04 UTCEPSS rescore
  55. 2026-06-30 23:20 UTCEPSS rescore
  56. 2026-06-29 14:04 UTCEPSS rescore
  57. 2026-06-29 14:04 UTCEPSS rescore
  58. 2026-06-28 14:05 UTCEPSS rescore
  59. 2026-06-28 04:54 UTCEPSS rescore
  60. 2026-06-28 04:54 UTCEPSS rescore
  61. 2026-06-27 03:07 UTCEPSS rescore
  62. 2026-06-27 03:06 UTCEPSS rescore
  63. 2026-06-25 13:48 UTCEPSS rescore
  64. 2026-06-25 13:48 UTCEPSS rescore
  65. 2026-06-24 14:03 UTCEPSS rescore
  66. 2026-06-24 14:03 UTCEPSS rescore
  67. 2026-06-23 21:31 UTCEPSS rescore
  68. 2026-06-23 21:31 UTCEPSS rescore
  69. 2026-06-22 19:35 UTCOSV refresh
  70. 2026-06-22 14:24 UTCEPSS rescore
  71. 2026-06-21 14:55 UTCEPSS rescore
  72. 2026-06-21 01:58 UTCEPSS rescore
  73. 2026-06-21 01:58 UTCEPSS rescore
  74. 2026-06-19 19:24 UTCEPSS rescore
  75. 2026-06-19 19:24 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-46700?
CVE-2021-46700 is a medium vulnerability published on February 19, 2022. In libsixel 1.8.6, sixelencoderoutputwithoutmacro (called from sixelencoderencode_frame in encoder.c) has a double free.
When was CVE-2021-46700 disclosed?
CVE-2021-46700 was first published in the National Vulnerability Database on February 19, 2022, with the most recent update on April 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-46700 actively exploited?
CVE-2021-46700 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 44.8% of all scored CVEs.
What is the CVSS score of CVE-2021-46700?
CVE-2021-46700 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2021-46700?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-46700, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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