CVE-2026-39829: Golang go.crypto · The RSA and DSA public key parsers did not enforce size limits on key parameters
Affects golang-go.cryptoSource GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10golang-go.cryptopkg:deb/ubuntu/golang-go.crypto?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10google-guest-agentpkg:deb/ubuntu/google-guest-agent?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10snapdpkg:deb/ubuntu/snapd?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSgoogle-guest-agentpkg:deb/ubuntu/google-guest-agent?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSsnapdpkg:deb/ubuntu/snapd?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu Pro 26.04 LTSgolang-go.cryptopkg:deb/ubuntu/golang-go.crypto?arch=source&distro=esm-apps/resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-39829 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-39829 (opens in a new tab)
- go.dev/issue/79565 (opens in a new tab)
- groups.google.com/g/golang-announce/c/a082jnz-LvI (opens in a new tab)
- go.dev/cl/781641 (opens in a new tab)
- go.dev/cl/781661 (opens in a new tab)
- pkg.go.dev/vuln/GO-2026-5018 (opens in a new tab)