VulnerabilityPublished 15 Jun 2026

CVE-2026-12205: TIMLEGGE Crypt::DSA · Reusing a Nonce, Key Pair in Encryption

Affects TIMLEGGE Crypt::DSASource CVE Database V5

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Not known to be exploited · CVSS 9.1 Critical : upgrade to 1.21 as a priority.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

9.1Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.21

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Crypt::DSA and Crypt-DSA to 1.21.

Affected software

Product	Affected	Fixed in
TIMLEGGECrypt::DSA	Affected <1.21	Fixed in 1.21
GitHubCrypt-DSA`pkg:github/Crypt-DSA`Other threats	Affected <1.21	Fixed in 1.21

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, avoid using Crypt::DSA versions prior to 1.21 for signing operations, or ensure that keys are not reused for multiple signatures. Consider regenerating keys if they have been used multiple times with affected versions, as they should be considered compromised.

Description

Crypt::DSA versions before 1.21 for Perl contain a vulnerability where the nonce used in digital signatures is reused across multiple signatures. This reuse occurs because the nonce material is cached in the Key object and never cleared, causing identical nonce values in subsequent signatures. As a result, private keys can be recovered if the same key signs more than once. This vulnerability is classified as CWE-323 and has a critical severity with a CVSS score of 9.1.

Impact

An attacker who obtains multiple signatures generated by the same key object in affected versions can recover the private key due to nonce reuse. This compromises the confidentiality and integrity of cryptographic operations relying on the private key, allowing impersonation or signature forgery. The vulnerability does not affect availability.

Summary

The Crypt::DSA Perl module versions prior to 1.21 suffer from a nonce reuse vulnerability in the signing process. Specifically, the Crypt::DSA::sign function caches the per-signature nonce in the Key object and does not clear it after use. Consequently, the first signature generates a nonce, but subsequent signatures with the same Key object reuse this nonce, resulting in identical 'r' values in signatures. This nonce reuse enables attackers to recover the private key, compromising the security of the signing key. Keys used to sign more than once with affected versions should be considered compromised.

CWE-323Reusing a Nonce, Key Pair in Encryption (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
Nonces should be used for the present occasion and only once.
Implementation
Refuse to reuse nonce values.
Implementation
Use techniques such as requiring incrementing, time based and/or challenge response to assure uniqueness of nonces.
OWASP Cheat Sheets
Forgot Password (opens in a new tab)
Transport Layer Protection (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.7.6 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Jun 2026, 15:18 UTC

WeaknessesCWE-323

Technical details

References

Community reviews

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