CPANSA-Crypt-Age-2026-85783: Crypt-Age vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-10-20T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-10-20T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | Severity | ||
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
Crypt::Age versions before 0.004 for Perl allow CPU exhaustion via an unbounded number of recipient stanzas, each costing an X25519 scalar multiplication in unwrap_file_key.
The header parser accepts any number of recipient stanzas, and unwrap_file_key tries every identity against every X25519 stanza. Each attempt runs a scalar multiplication, an HKDF and a ChaCha20-Poly1305 open. The header MAC cannot be checked first, because its key comes from the file key, which only a successful unwrap produces.
Each stanza is 98 bytes of attacker-chosen header and buys one scalar multiplication per identity held, and the file is rejected only after every one of them has run. A caller reaches this through decrypt, decrypt_file or decrypt_filehandle whenever it decrypts a file it did not write.
Vulnerabilities
CVE-2026-85783
Vulnerability DescriptionCrypt::Age versions before 0.004 for Perl allow CPU exhaustion via an unbounded number of recipient stanzas, each costing an X25519 scalar multiplication in unwrap_file_key.
The header parser accepts any number of recipient stanzas, and unwrap_file_key tries every identity against every X25519 stanza. Each attempt runs a scalar multiplication, an HKDF and a ChaCha20-Poly1305 open. The header MAC cannot be checked first, because its key comes from the file key, which only a successful unwrap produces.
Each stanza is 98 bytes of attacker-chosen header and buys one scalar multiplication per identity held, and the file is rejected only after every one of them has run. A caller reaches this through decrypt, decrypt_file or decrypt_filehandle whenever it decrypts a file it did not write.
| Weakness | CWE-405 : Asymmetric Resource Consumption (Amplification) |
|---|
Product status
Known affected
| Product | Score | ||||
|---|---|---|---|---|---|
| Crypt-Age less than 0.004 |
|
Fixed
- Crypt-Age greater than or equal 0.004
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Crypt-Age-2026-85783 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-crypt-age-2026-85783.json - https://metacpan.org/release/GETTY/Crypt-Age-0.004/changes external
https://metacpan.org/release/GETTY/Crypt-Age-0.004/changes - http://www.openwall.com/lists/oss-security/2026/10/20/39 external
http://www.openwall.com/lists/oss-security/2026/10/20/39 - CVE-2026-85783 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-85783
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Tue Oct 20 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/