CVE-2026-39829
The RSA and DSA public key parsers did not enforce size limits on key parameters.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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 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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.47% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-347, CWE-1284
- Affected
- golang/crypto
- Source
- security@golang.org
References
- https://go.dev/cl/781641Issue Tracking
- https://go.dev/cl/781661Issue Tracking
- https://go.dev/issue/79565Issue Tracking
- https://groups.google.com/g/golang-announce/c/a082jnz-LvIMailing List
- https://pkg.go.dev/vuln/GO-2026-5018Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:26546
- https://access.redhat.com/errata/RHSA-2026:26547
- https://access.redhat.com/errata/RHSA-2026:29455
- https://access.redhat.com/errata/RHSA-2026:35833
- https://access.redhat.com/errata/RHSA-2026:36199
- https://access.redhat.com/errata/RHSA-2026:36207
- https://access.redhat.com/errata/RHSA-2026:36319
- https://access.redhat.com/errata/RHSA-2026:36625
- https://access.redhat.com/errata/RHSA-2026:36648
- https://access.redhat.com/errata/RHSA-2026:36651
- https://access.redhat.com/errata/RHSA-2026:36796
- https://access.redhat.com/errata/RHSA-2026:36797
- https://access.redhat.com/errata/RHSA-2026:36808
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/errata/RHSA-2026:36883
- https://access.redhat.com/errata/RHSA-2026:37072
- https://access.redhat.com/errata/RHSA-2026:37123
- https://access.redhat.com/errata/RHSA-2026:37268
- https://access.redhat.com/errata/RHSA-2026:37271
- https://access.redhat.com/errata/RHSA-2026:37272
- https://access.redhat.com/errata/RHSA-2026:37278
- https://access.redhat.com/errata/RHSA-2026:37286
- https://access.redhat.com/errata/RHSA-2026:37296
- https://access.redhat.com/errata/RHSA-2026:37387
- https://access.redhat.com/errata/RHSA-2026:40118
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.