PYSEC-2026-70

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/jwcrypto/PYSEC-2026-70.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-70
Aliases
Published
2026-04-07T20:16:32.133Z
Modified
2026-05-21T15:00:14.336277076Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
[none]
Details

JWCrypto implements JWK, JWS, and JWE specifications using python-cryptography. Prior to 1.5.7, an unauthenticated attacker can exhaust server memory by sending crafted JWE tokens with ZIP compression. The existing patch for CVE-2024-28102 limits input token size to 250KB but does not validate the decompressed output size. An unauthenticated attacker can cause memory exhaustion on memory-constrained systems. A token under the 250KB input limit can decompress to approximately 100MB. This vulnerability is fixed in 1.5.7.

References

Affected packages

PyPI / jwcrypto

Package

Name
jwcrypto
View open source insights on deps.dev
Purl
pkg:pypi/jwcrypto

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.5.7

Affected versions

0.*
0.2.0
0.2.1
0.3.0
0.3.1
0.4.0
0.4.1
0.4.2
0.5.0
0.6.0
0.7
0.8
0.9
0.9.1
1.*
1.0
1.2
1.3
1.3.1
1.4
1.4.1
1.4.2
1.5.0
1.5.1
1.5.2
1.5.3
1.5.4
1.5.5
1.5.6

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/jwcrypto/PYSEC-2026-70.yaml"