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CVE-2018-10903
A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length.…
High7.5EPSS 3.2%
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.0 | High7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Modified | 3.0 | High7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 3.2% · top 12% of all CVEs (5 Nov 2026)
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
[UNKNOWN] · python-cryptography
- affected 2.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIcryptographyGHSA-fcf9-3qw3-gxmj (opens in a new tab)
References (4)
- RHSA-2018:3600 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- USN-3720-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-fcf9-3qw3-gxmj (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2018-10903)Record last updated .