CVE-2026-42256
Description
net-imap vulnerable to denial of service via high iteration count for `SCRAM-*` authentication
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-42256
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-42256.html
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/security/advisories/GHSA-87pf-fpwv-p7m7
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/releases/tag/v0.6.4
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/releases/tag/v0.5.14
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/releases/tag/v0.4.24
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4
Vendor advisory: security-advisories@github.com — https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bullseye | affected | |
| debian | bookworm | affected | |
| debian | forky | affected | |
| debian | sid | affected | |
| debian | trixie | affected | |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| RubyGems | net-imap | !< 0.4.0||<~> 0.4.24 | ~> 0.4.24 |
| RubyGems | net-imap | >=0.6.0,<0.6.4 | 0.6.4 |
| RubyGems | net-imap | >=0.5.0,<0.5.14 | 0.5.14 |
| RubyGems | net-imap | >=0.4.0,<0.4.24 | 0.4.24 |
| RUBYGEMS | net-imap | >= 0.4.0, <= 0.4.23 | 0.4.24 |
| RUBYGEMS | net-imap | >= 0.5.0, <= 0.5.13 | 0.5.14 |
| RUBYGEMS | net-imap | >= 0.6.0, <= 0.6.3 | 0.6.4 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| ruby-lang | net\ | {"startIncluding":"0.4.0","endExcluding":"0.4.24"} | 0.4.24 |
References
- https://github.com/ruby/net-imap/security/advisories/GHSA-87pf-fpwv-p7m7
- https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612
- https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4
- https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758
- https://github.com/ruby/net-imap/releases/tag/v0.4.24
- https://github.com/ruby/net-imap/releases/tag/v0.5.14
- https://github.com/ruby/net-imap/releases/tag/v0.6.4
- https://www.suse.com/security/cve/CVE-2026-42256.html
- https://nvd.nist.gov/vuln/detail/CVE-2026-42256
- https://github.com/ruby/net-imap
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/net-imap/CVE-2026-42256.yml
- https://www.rfc-editor.org/rfc/rfc7804.html#page-15
- https://security-tracker.debian.org/tracker/CVE-2026-42256
- https://github.com/advisories/GHSA-87pf-fpwv-p7m7
CWEs
CWE-770 CWE-1322
Verify integrity in audit chain (admin only). AS-IS.