CVE-2026-39829
Published: 22 May 2026
Summary
CVE-2026-39829 is a high-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Golang Crypto. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 19.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-31396
Vulnerability details
The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be…
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triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE enables CPU exhaustion DoS via crafted public keys on unauthenticated public-key auth in a network service (e.g. SSH), directly mapping to public-facing app exploitation and application exploitation for endpoint DoS.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.
Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.
PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.
Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.
Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.
Integrity tools commonly rely on cryptographic signatures whose improper validation this weakness covers.
Authenticity validation commonly relies on cryptographic signature or certificate checks that this control enforces.