CVE-2026-63435
CVE-2026-63435 · Mail: Email address spoofing via malformed RFC 2047 encoded-words
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Mail is an internet library for Ruby designed to handle email generation, parsing, and sending. Prior to 2.9.1, Mail::Utilities.q_value_decode and Mail::Utilities.b_value_decode used a single String#match and an overly greedy charset capture to decode only the first RFC 2047 encoded-word and mishandle surrounding or subsequent text. A crafted malformed encoded-word in an address display name or local part could cross ? delimiters and make decoded From, To, or Reply-To header values differ from the raw values inspected by a human reviewer or downstream parser, enabling apparent sender or recipient spoofing, phishing, or authorization-check bypass. This issue is fixed in version 2.9.1.
CVSS 5.3 · Medium · EPSS 0.4% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
mail
- Versions
- < 2.9.1: Affected
No fix published
ruby-mail Debian:12
- Versions
- 2.7.1+dfsg1-2
- 2.8.1+dfsg1-1
- 2.8.1+dfsg1-2
- 2.9.0+dfsg1-1
- 2.9.1-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby-mail Debian:13
- Versions
- 2.8.1+dfsg1-2
- 2.9.0+dfsg1-1
- 2.9.1-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby-mail Debian:14
- Versions
- 2.8.1+dfsg1-2
- 2.9.0+dfsg1-1
- Affected ranges
- ECOSYSTEM: < 2.9.1-1
Update to 2.9.1-1
jruby Ubuntu:Pro:14.04:LTS
- Versions
- 1.5.6-5ubuntu1
- 1.5.6-6
- 1.5.6-7
- 1.5.6-9+deb8u2build0.14.04.1~esm2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby2.3 Ubuntu:Pro:16.04:LTS
- Versions
- 2.3.0-1
- 2.3.0-2
- 2.3.0-4ubuntu2
- 2.3.0-4ubuntu3
- 2.3.0-5ubuntu1
- 2.3.1-2~16.04
- 2.3.1-2~16.04.2
- 2.3.1-2~16.04.4
- 2.3.1-2~16.04.5
- 2.3.1-2~16.04.6
- 2.3.1-2~16.04.7
- 2.3.1-2~16.04.9
- 2.3.1-2~16.04.10
- 2.3.1-2~16.04.11
- 2.3.1-2~16.04.12
- 2.3.1-2~ubuntu16.04.13
- 2.3.1-2~ubuntu16.04.14
- 2.3.1-2~ubuntu16.04.15
- 2.3.1-2~ubuntu16.04.16
- 2.3.1-2~ubuntu16.04.16+esm1
- 2.3.1-2~ubuntu16.04.16+esm2
- 2.3.1-2~ubuntu16.04.16+esm3
- 2.3.1-2~ubuntu16.04.16+esm4
- 2.3.1-2~ubuntu16.04.16+esm5
- 2.3.1-2~ubuntu16.04.16+esm6
- 2.3.1-2~ubuntu16.04.16+esm7
- 2.3.1-2~ubuntu16.04.16+esm8
- 2.3.1-2~ubuntu16.04.16+esm9
- 2.3.1-2~ubuntu16.04.16+esm10
- 2.3.1-2~ubuntu16.04.16+esm11
- 2.3.1-2~ubuntu16.04.16+esm12
- 2.3.1-2~ubuntu16.04.16+esm14
- 2.3.1-2~ubuntu16.04.16+esm15
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
jruby Ubuntu:16.04:LTS
- Versions
- 1.7.21-2ubuntu4
- 1.7.22-1ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby2.5 Ubuntu:Pro:18.04:LTS
- Versions
- 2.5.0~preview1-1ubuntu2
- 2.5.0-4ubuntu1
- 2.5.0-4ubuntu4
- 2.5.0-5ubuntu1
- 2.5.0-6ubuntu1
- 2.5.1-1ubuntu1
- 2.5.1-1ubuntu1.1
- 2.5.1-1ubuntu1.2
- 2.5.1-1ubuntu1.4
- 2.5.1-1ubuntu1.5
- 2.5.1-1ubuntu1.6
- 2.5.1-1ubuntu1.7
- 2.5.1-1ubuntu1.8
- 2.5.1-1ubuntu1.9
- 2.5.1-1ubuntu1.10
- 2.5.1-1ubuntu1.11
- 2.5.1-1ubuntu1.12
- 2.5.1-1ubuntu1.13
- 2.5.1-1ubuntu1.14
- 2.5.1-1ubuntu1.15
- 2.5.1-1ubuntu1.16
- 2.5.1-1ubuntu1.16+esm1
- 2.5.1-1ubuntu1.16+esm3
- 2.5.1-1ubuntu1.16+esm4
- 2.5.1-1ubuntu1.16+esm5
- 2.5.1-1ubuntu1.16+esm6
- 2.5.1-1ubuntu1.16+esm7
- 2.5.1-1ubuntu1.16+esm8
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
jruby Ubuntu:18.04:LTS
- Versions
- 9.1.13.0-1
- 9.1.17.0-1~18.04
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby2.7 Ubuntu:Pro:20.04:LTS
- Versions
- 2.7.0-1
- 2.7.0-2
- 2.7.0-3
- 2.7.0-4
- 2.7.0-4ubuntu1
- 2.7.0-5ubuntu1
- 2.7.0-5ubuntu1.1
- 2.7.0-5ubuntu1.2
- 2.7.0-5ubuntu1.3
- 2.7.0-5ubuntu1.4
- 2.7.0-5ubuntu1.5
- 2.7.0-5ubuntu1.6
- 2.7.0-5ubuntu1.7
- 2.7.0-5ubuntu1.8
- 2.7.0-5ubuntu1.9
- 2.7.0-5ubuntu1.10
- 2.7.0-5ubuntu1.11
- 2.7.0-5ubuntu1.12
- 2.7.0-5ubuntu1.13
- 2.7.0-5ubuntu1.14
- 2.7.0-5ubuntu1.15
- 2.7.0-5ubuntu1.16
- 2.7.0-5ubuntu1.17
- 2.7.0-5ubuntu1.18
- 2.7.0-5ubuntu1.18+esm1
- 2.7.0-5ubuntu1.18+esm3
- 2.7.0-5ubuntu1.18+esm4
- 2.7.0-5ubuntu1.18+esm5
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
jruby Ubuntu:20.04:LTS
- Versions
- 9.1.17.0-3
- 9.1.17.0-3build5
- 9.1.17.0-3build6
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby3.0 Ubuntu:22.04:LTS
- Versions
- 3.0.2-5ubuntu1
- 3.0.2-7
- 3.0.2-7ubuntu2
- 3.0.2-7ubuntu2.1
- 3.0.2-7ubuntu2.2
- 3.0.2-7ubuntu2.3
- 3.0.2-7ubuntu2.4
- 3.0.2-7ubuntu2.5
- 3.0.2-7ubuntu2.6
- 3.0.2-7ubuntu2.7
- 3.0.2-7ubuntu2.8
- 3.0.2-7ubuntu2.10
- 3.0.2-7ubuntu2.11
- 3.0.2-7ubuntu2.12
- 3.0.2-7ubuntu2.13
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
jruby Ubuntu:24.04:LTS
- Versions
- 9.3.9.0+ds-1
- 9.4.5.0+ds-1
- 9.4.5.0+ds-1ubuntu1
- 9.4.6.0+ds-1ubuntu3
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby3.2 Ubuntu:24.04:LTS
- Versions
- 3.2.3-1
- 3.2.3-1build2
- 3.2.3-1build3
- 3.2.3-1ubuntu0.24.04.1
- 3.2.3-1ubuntu0.24.04.3
- 3.2.3-1ubuntu0.24.04.5
- 3.2.3-1ubuntu0.24.04.6
- 3.2.3-1ubuntu0.24.04.7
- 3.2.3-1ubuntu0.24.04.8
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
jruby Ubuntu:26.10
- Versions
- 9.4.8.0+ds-3ubuntu1
- 9.4.14.0+ds-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby3.3 Ubuntu:26.10
- Versions
- 3.3.8-2ubuntu3
- 3.3.8-2.2ubuntu4
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
jruby Ubuntu:26.04:LTS
- Versions
- 9.4.8.0+ds-3ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
ruby3.3 Ubuntu:26.04:LTS
- Versions
- 3.3.8-2ubuntu2
- 3.3.8-2ubuntu3
- 3.3.8-2ubuntu3.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published