CVE-2023-39533

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 1.5% (73rd percentile of EPSS-scored CVEs). 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
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.5%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

go-libp2p is the Go implementation of the libp2p Networking Stack. Prior to versions 0.27.8, 0.28.2, and 0.29.1 malicious peer can use large RSA keys to run a resource exhaustion attack & force a node to spend time doing signature verification of the large key. This vulnerability is present in the core/crypto module of go-libp2p and can occur during the Noise handshake and the libp2p x509 extension verification step. To prevent this attack, go-libp2p versions 0.27.8, 0.28.2, and 0.29.1 restrict RSA keys to <= 8192 bits. To protect one's application, it is necessary to update to these patch releases and to use the updated Go compiler in 1.20.7 or 1.19.12. There are no known workarounds for this issue.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100CISA SSVC

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.5%
EPSS %ILE
73rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 8, 2023

Last Modified

September 1, 2026

Advisory Details (9)

Auto-updated Sep 1, 2026
Patch available. Sources: github, github_pr, github_commit.
generic

NRDAX-T0205 - Pre-Handshake Crypto CPU Burn · NRDAX

https://nrdax.com/techniques/NRDAX-T0205-pre-handshake-crypto-cpu-burn
github_commit

commit e30fcf7dfd47 (libp2p/go-libp2p)

Fix landed in libp2p/go-libp2p commit e30fcf7dfd47 — awaiting tagged release

https://github.com/libp2p/go-libp2p/commit/e30fcf7dfd4715ed89a5e68d7a4f774d3b9aa92d
github_commit

commit 445be526aea4 (libp2p/go-libp2p)

Fix landed in libp2p/go-libp2p commit 445be526aea4 — awaiting tagged release

https://github.com/libp2p/go-libp2p/commit/445be526aea4ee0b1fa5388aa65d32b2816d3a00
github_commit

commit 0cce607219f3 (libp2p/go-libp2p)

Fix landed in libp2p/go-libp2p commit 0cce607219f3 — awaiting tagged release

https://github.com/libp2p/go-libp2p/commit/0cce607219f3710addc7e18672cffd1f1d912fbb
github_commit

commit 2350afd2e8ab (golang/go)

Fix landed in golang/go commit 2350afd2e8ab — awaiting tagged release

https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017
github_pr Patch Available

update qtls to restrict RSA keys in certificates to <= 8192 bits

Patch available: quic-go/quic-go v0.42.0 (PR #4012 merged 2023-08-03)

https://github.com/quic-go/quic-go/pull/4012
github_pr Patch Available

core/crypto: restrict RSA keys to <= 8192 bits

Patch available: libp2p/go-libp2p v0.35.3 (PR #2454 merged 2023-08-03)

https://github.com/libp2p/go-libp2p/pull/2454
generic

crypto/tls: verifying certificate chains containing large RSA keys is slow [CVE-2023-29409] · Issue #61460 · golang/go · GitHub

https://github.com/golang/go/issues/61460
githubMentions a patch (unverified)

libp2p nodes vulnerable to attack using large RSA keys · Advisory · libp2p/go-libp2p · GitHub

https://github.com/libp2p/go-libp2p/security/advisories/GHSA-876p-8259-xjgg

Vendor Advisories for CVE-2023-39533(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/libp2p/go-libp2p0.29.0
  • every version up to 0.27.8: fixed in 0.27.8
  • 0.28.0 up to 0.28.2: fixed in 0.28.2
  • 0.29.0 up to 0.29.1: fixed in 0.29.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 32× 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 201 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

Same product

2 shown

Go:github.com/libp2p/go-libp2p

Frequently asked(5)

What is CVE-2023-39533?
CVE-2023-39533 is a high vulnerability published on August 8, 2023. go-libp2p is the Go implementation of the libp2p Networking Stack. Prior to versions 0.27.8, 0.28.2, and 0.29.1 malicious peer can use large RSA keys to run a resource exhaustion attack & force a node to spend time doing signature verification of the large key. This vulnerability is present in the…
When was CVE-2023-39533 disclosed?
CVE-2023-39533 was first published on August 8, 2023, with the most recent update on September 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-39533 actively exploited?
CVE-2023-39533 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.5% probability of exploitation in the next 30 days (73rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-39533?
CVE-2023-39533 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2023-39533?
A fix for CVE-2023-39533 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2023-39533 are linked in the Vendor Advisories panel on this page.

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