Python-RSA before 4.1 ignores leading '\0' bytes during decryption of ciphertext. This could conceivably have a security-relevant impact, e.g., by helping an attacker to infer that an application uses Python-RSA, or if the length of accepted ciphertext affects application behavior (such as by causing excessive memory allocation).
CVE-2020-13757
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 73% 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).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 68.4%
- KEV
- Not listed
Published
June 1, 2020
Last Modified
November 21, 2024
References (10)
- cve@mitrehttps://github.com/sybrenstuvel/python-rsa/issues/146
- cve@mitrehttps://github.com/sybrenstuvel/python-rsa/issues/146#issuecomment-641845667
- cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KILTHBHNSDUCYV22ODLOKTICJJ7JQIQ/
- cve@mitrehttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZYB65VNILRBTXL6EITQTH2PZPK7I23MW/
- cve@mitrehttps://usn.ubuntu.com/4478-1/
- af854a3a-2127-422b-91ae-364da2661108https://github.com/sybrenstuvel/python-rsa/issues/146
- af854a3a-2127-422b-91ae-364da2661108https://github.com/sybrenstuvel/python-rsa/issues/146#issuecomment-641845667
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KILTHBHNSDUCYV22ODLOKTICJJ7JQIQ/
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZYB65VNILRBTXL6EITQTH2PZPK7I23MW/
- af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/4478-1/
Patch Availability(4)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | python3-rsa (3.1.2-1ubuntu0.1+esm1) @ trusty | 2026-05-27 | ubuntu |
| ubuntu | python3-rsa (3.2.3-1.1ubuntu0.1~esm1) @ xenial | 2026-05-27 | ubuntu |
| redhat | python-rsa-0:4.5-2.el7 | 2020-08-27 | redhat |
| redhat | python-rsa-0:4.5-1.el7 | 2020-08-18 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| rsa | 1.1 ... 4.0 (23 versions) | 4.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(4)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 8× in last 7d / 47× 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 08:24 UTCEPSS rescore
- 2026-07-09 19:06 UTCEPSS rescore
- 2026-07-08 15:11 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
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- 2026-07-05 02:27 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-07-01 20:31 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
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- 2026-06-29 14:04 UTCEPSS rescore
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- 2026-06-28 14:05 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
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- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
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- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
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- 2026-06-23 21:31 UTCEPSS rescore
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- 2026-06-18 17:50 UTCEPSS rescore
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- 2026-06-15 17:46 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
- 2026-06-14 23:15 UTCEPSS rescore
- 2026-06-14 02:13 UTCOSV refresh
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-13 22:58 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-11 13:58 UTCEPSS rescore
- 2026-06-10 22:16 UTCEPSS rescore
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- 2026-06-10 13:20 UTCEPSS rescore
- 2026-06-08 14:15 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 13:45 UTCEPSS rescore
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- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 22:45 UTCEPSS rescore
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- 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
- 2026-05-29 13:42 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 03:09 UTCEG score recompute
- 2026-05-27 03:09 UTCVendor advisory
- 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
Frequently asked(5)
What is CVE-2020-13757?
When was CVE-2020-13757 disclosed?
Is CVE-2020-13757 actively exploited?
What is the CVSS score of CVE-2020-13757?
How do I remediate CVE-2020-13757?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-13757
Is Your Infrastructure Affected by CVE-2020-13757?
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