Tendermint before versions 0.33.3, 0.32.10, and 0.31.12 has a denial-of-service vulnerability. Tendermint does not limit the number of P2P connection requests. For each p2p connection, it allocates XXX bytes. Even though this memory is garbage collected once the connection is terminated (due to duplicate IP or reaching a maximum number of inbound peers), temporary memory spikes can lead to OOM (Out-Of-Memory) exceptions. Additionally, Tendermint does not reclaim activeID of a peer after it's removed in Mempool reactor. This does not happen all the time. It only happens when a connection fails (for any reason) before the Peer is created and added to all reactors. RemovePeer is therefore called before AddPeer, which leads to always growing memory (activeIDs map). The activeIDs map has a maximum size of 65535 and the node will panic if this map reaches the maximum. An attacker can create a lot of connection attempts (exploiting above denial of service), which ultimately will lead to the node panicking. These issues are patched in Tendermint 0.33.3 and 0.32.10.
CVE-2020-5303
This low-severity CVE scores 3.1 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 45% 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).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 3.1
- EG Score
- 3.1(medium)
- EPSS
- 67.9%
- KEV
- Not listed
Published
April 10, 2020
Last Modified
November 21, 2024
References (6)
- security-advisories@githubhttps://github.com/tendermint/tendermint/commit/e2d6859afd7dba4cf97c7f7d412e7d8fc908d1cd
- security-advisories@githubhttps://github.com/tendermint/tendermint/security/advisories/GHSA-v24h-pjjv-mcp6
- security-advisories@githubhttps://hackerone.com/reports/820317
- af854a3a-2127-422b-91ae-364da2661108https://github.com/tendermint/tendermint/commit/e2d6859afd7dba4cf97c7f7d412e7d8fc908d1cd
- af854a3a-2127-422b-91ae-364da2661108https://github.com/tendermint/tendermint/security/advisories/GHSA-v24h-pjjv-mcp6
- af854a3a-2127-422b-91ae-364da2661108https://hackerone.com/reports/820317
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/tendermint/tendermint | — | 0.32.10 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 46× 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.
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-09 19:07 UTCEPSS rescore
- 2026-07-08 15:12 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-02 16:57 UTCEPSS rescore
- 2026-07-02 01:47 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-29 14:04 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
Show 55 moreShow fewer
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
- 2026-06-18 17:51 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:46 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
- 2026-06-14 05:13 UTCOSV refresh
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-12 23:10 UTCEPSS rescore
- 2026-06-12 23:10 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
- 2026-06-10 13:20 UTCEPSS rescore
- 2026-06-08 14:15 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-07 15:23 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-02 20:11 UTCEPSS rescore
- 2026-06-01 13:50 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 22:29 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-27 05:18 UTCEG score recompute
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-25 21:46 UTCOSV refresh
Related CVEs(same CWE)
Same CWE
10 shownCWE-787
- CVE-2007-0158EG 9.8CRITICAL
- CVE-2007-0899EG 9.8CRITICAL
- CVE-2011-2462EG 9.8 KEVEPSS 100%CRITICAL
- CVE-2010-20115EG 9.3CRITICAL
- CVE-2010-4398NVD 7.8EG 9.0 KEVEPSS 94%HIGH
- CVE-2010-3333NVD 7.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-2883NVD 7.3EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-1297NVD 7.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2009-3953NVD 8.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2009-3129NVD 7.8EG 9.0 KEVEPSS 100%HIGH
Frequently asked(5)
What is CVE-2020-5303?
When was CVE-2020-5303 disclosed?
Is CVE-2020-5303 actively exploited?
What is the CVSS score of CVE-2020-5303?
How do I remediate CVE-2020-5303?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-5303
Is Your Infrastructure Affected by CVE-2020-5303?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.