CVE-2021-32765

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 2.0%, top 21% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 8.8Exploit: None knownExposed: 0

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

Hiredis is a minimalistic C client library for the Redis database. In affected versions Hiredis is vulnurable to integer overflow if provided maliciously crafted or corrupted RESP mult-bulk protocol data. When parsing multi-bulk (array-like) replies, hiredis fails to check if count * sizeof(redisReply*) can be represented in SIZE_MAX. If it can not, and the calloc() call doesn't itself make this check, it would result in a short allocation and subsequent buffer overflow. Users of hiredis who are unable to update may set the maxelements context option to a value small enough that no overflow is possible.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity88% × 45%
Exploitation2% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
81%
KEV
Not listed

Published

October 4, 2021

Last Modified

November 21, 2024

Advisory Details (6)

Auto-updated Aug 27, 2026
Patch available. Sources: github_commit, github.
generic

hiredis, hiredis-py: Multiple Vulnerabilities (GLSA 202210-32) — Gentoo security

https://security.gentoo.org/glsa/202210-32
generic Patch Available

[SECURITY] [DLA 2783-1] hiredis security update

https://lists.debian.org/debian-lts-announce/2021/10/msg00007.html
github Patch Available

Integer Overflow to Buffer Overflow in hiredis · Advisory · redis/hiredis · GitHub

https://github.com/redis/hiredis/security/advisories/GHSA-hfm9-39pp-55p2
github_commit Patch Available

commit 76a7b10005c7 (redis/hiredis)

Patch available: redis/hiredis v1.0.2 (contains commit 76a7b10005c7)

https://github.com/redis/hiredis/commit/76a7b10005c70babee357a7d0f2becf28ec7ed1e
generic

MEM07-C. Ensure that the arguments to calloc(), when multiplied, do not wrap | CERT Secure Coding

https://wiki.sei.cmu.edu/confluence/display/c/MEM07-C.+Ensure+that+the+arguments+to+calloc%28%29%2C+when+multiplied%2C+do+not+wrap
generic

NetApp Product Security

https://security.netapp.com/advisory/ntap-20211104-0003/

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
hiredis0.14.1-1 ... 1.2.0-6 (16 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
hiredis—0.14.1-2—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
hiredis—0.14.1-2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
hiredis—0.14.1-2—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 33× 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 152 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-32765?
CVE-2021-32765 is a high vulnerability published on October 4, 2021. Hiredis is a minimalistic C client library for the Redis database. In affected versions Hiredis is vulnurable to integer overflow if provided maliciously crafted or corrupted RESP mult-bulk protocol data. When parsing multi-bulk (array-like) replies, hiredis fails to check if count…
When was CVE-2021-32765 disclosed?
CVE-2021-32765 was first published in the National Vulnerability Database on October 4, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-32765 actively exploited?
CVE-2021-32765 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 19.2% of all scored CVEs.
What is the CVSS score of CVE-2021-32765?
CVE-2021-32765 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2021-32765?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-32765, 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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