Mishandling of comma during folding and unicode-encoding of email headers
During an address list folding when a separating comma ends up on a folded line and that line is to be unicode-encoded then the separator itself is also unicode-encoded. Expected behavior is that the separating comma remains a plan comma. This can result in the address header being misinterpreted by some mail servers.
02 / AFFECTED SOFTWARE
Affected packages
185 explicit affected versions
338 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
During an address list folding when a separating comma ends up on a folded line and that line is to be unicode-encoded then the separator itself is also unicode-encoded. Expected behavior is that the separating comma remains a plan comma. This can result in the address header being misinterpreted by some mail servers.
During an address list folding when a separating comma ends up on a folded line and that line is to be unicode-encoded then the separator itself is also unicode-encoded. Expected behavior is that the separating comma remains a plan comma. This can result in the address header being misinterpreted by some mail servers.
During an address list folding when a separating comma ends up on a folded line and that line is to be unicode-encoded then the separator itself is also unicode-encoded. Expected behavior is that the separating comma remains a plan comma. This can result in the address header being misinterpreted by some mail servers.
During an address list folding when a separating comma ends up on a folded line and that line is to be unicode-encoded then the separator itself is also unicode-encoded. Expected behavior is that the separating comma remains a plan comma. This can result in the address header being misinterpreted by some mail servers.
During an address list folding when a separating comma ends up on a folded line and that line is to be unicode-encoded then the separator itself is also unicode-encoded. Expected behavior is that the separating comma remains a plan comma. This can result in the address header being misinterpreted by some mail servers.
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/1xxx/CVE-2025-1795.json
- https://github.com/python/cpython
- https://github.com/python/cpython/commit/09fab93c3d857496c0bd162797fab816c311ee48
- https://github.com/python/cpython/commit/70754d21c288535e86070ca7a6e90dcb670b8593
- https://github.com/python/cpython/commit/9148b77e0af91cdacaa7fe3dfac09635c3fe9a74
- https://github.com/python/cpython/commit/a4ef689ce670684ec132204b1cd03720c8e0a03d
- https://github.com/python/cpython/commit/d4df3c55e4c5513947f907f24766b34d2ae8c090
- https://github.com/python/cpython/issues/100884
- https://github.com/python/cpython/pull/100885
- https://github.com/python/cpython/pull/119099
- https://lists.debian.org/debian-lts-announce/2025/03/msg00013.html
- https://mail.python.org/archives/list/[email protected]/thread/MB62IZMEC3UM6SGHP5LET5JX2Y7H4ZUR/
- https://nvd.nist.gov/vuln/detail/CVE-2025-1795