Vulnerability · CVE-2026-116587

Go JOSE: DoS when parsing JWKs that contain RSA keys

Q: Which versions are affected?

Compare what you have installed with 0 → 3.0.5, 0 → 4.1.6, <= 3.0.5, <= 4.1.5. Compare the installed version with the linked vendor advisory before you change production.

Q: What should an analyst verify?

CWE-407; CWE-770: Allocation of Resources Without Limits or Throttling. EPSS 0.37%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Published Oct 26, 2026 · catalog updated Oct 27, 2026 · Go JOSE: DoS when

Last checked Oct 28, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-116587. EPSS is 0.37%. Act only if a listed version of Go JOSE: DoS when is installed.

Gaps on this record

The stored product name is a package slug. The name on this page is taken from the title (Go JOSE: DoS when).
No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

CVE-2026-34986 · High

Severity: High7.5
Known exploitation: Not in CISA/VulnCheck KEV
EPSS: 0.37%
Remediation: Version ranges on file
Affected products: Go github.com/go-jose/go-jose/v3 · Go github.com/go-jose/go-jose/v4 · go github.com/go-jose/go-jose/v3 · go github.com/go-jose/go-jose/v4 · golang github.com · vendor go-jose go-jose

### Summary A crafted RSA key inside a JWK can cause operations that parse JWKs to consume excess CPU. ### Details go-jose does not check for bounds on RSA modulus and primes before validating them. Values are passed directly to . On Go 1.24+, this takes cubic time complexity with respect to the RSA modulus and primes. This allows an attacker to supply a crafted JWK to consume excessive CPU. https://github.com/go-jose/go-jose/blob/5b371aecfcf7aabe06068d67da4344591ecddc76/jwk.go#L655-L700 ### Proof of concept No special configuration of go-jose is required to reproduce this vulnerability. ### Impact Denial of service vulnerability. Any application that uses go-jose to parse JWKs from untrusted sources is affected and should patch immediately. ### Credits Reported by Yuval Saggie and Mor Weinberger (powered by Echo Frontier)

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

Go github.com/go-jose/go-jose/v30 → 3.0.5
Go github.com/go-jose/go-jose/v40 → 4.1.6
go github.com/go-jose/go-jose/v3<= 3.0.5
go github.com/go-jose/go-jose/v4<= 4.1.5
golang github.comversion unspecified
vendor go-jose go-joseversion unspecified

How to fix CVE-2026-116587

Upgrade
CVE-2026-116587 lists a fix boundary at 3.0.5. Compare the installed build with that boundary before you change production.
Version check
Affected <= 3.0.5
Advisory
Open the cve_org record and follow its fix.
Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-116587. EPSS is 0.37%. Act only if a listed version of Go JOSE: DoS when is installed.

Which versions are affected?

Compare what you have installed with 0 → 3.0.5, 0 → 4.1.6, <= 3.0.5, <= 4.1.5. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-407; CWE-770: Allocation of Resources Without Limits or Throttling. EPSS 0.37%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Repository · github.com

Timeline

Detection, updates, and resolution for this record.

Oct 27, 2026 · GitHub Advisory Database
Detected
### Summary A crafted RSA key inside a JWK can cause operations that parse JWKs to consume excess CPU. ### Details go-jose does not check for bounds on RSA modulus and primes before validating them. Values are passed directly to . On Go 1.24+, this takes cubic time complexity with respect to the RSA modulus and primes. This allows an attacker to supply a crafted JWK to consume excessive CPU. https
Oct 27, 2026 · GitHub Advisory Database
Updated
### Summary A crafted RSA key inside a JWK can cause operations that parse JWKs to consume excess CPU. ### Details go-jose does not check for bounds on RSA modulus and primes before validating them. Values are passed directly to . On Go 1.24+, this takes cubic time complexity with respect to the RSA modulus and primes. This allows an attacker to supply a crafted JWK to consume excessive CPU. https
Oct 27, 2026 · Go Vulnerability Database
Fix available
github.com/go-jose/go-jose/v4 fixed in 4.1.6
Oct 27, 2026 · Go Vulnerability Database
Fix available
github.com/go-jose/go-jose/v4 fixed in 4.1.6
Oct 27, 2026 · Go Vulnerability Database
Fix available
github.com/go-jose/go-jose/v3 fixed in 3.0.5
Oct 27, 2026 · Go Vulnerability Database
Updated
### Summary A crafted RSA key inside a JWK can cause operations that parse JWKs to consume excess CPU. ### Details go-jose does not check for bounds on RSA modulus and primes before validating them. Values are passed directly to . On Go 1.24+, this takes cubic time complexity with respect to the RSA modulus and primes. This allows an attacker to supply a crafted JWK to consume excessive CPU. https

Sources

CVE.orgVulnerability recordCVE-2026-116587
Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.6, go-jose parses attacker-controlled RSA modulus
cve.org
GitHub Advisory DatabasePackage advisoryGHSA-mgcc-cww5-fp2q
GitHub Advisory Database record mirrored by OSV.
github.com
GitLab Advisory DatabasePackage advisoryCVE-2026-116587
A crafted RSA key inside a JWK can cause operations that parse JWKs to consume excess CPU.
advisories.gitlab.com
Go Vulnerability DatabasePackage advisoryGHSA-mgcc-cww5-fp2q
Go JOSE: DoS when parsing JWKs that contain RSA keys
osv.dev
OpenSSF OSV / OSV ScannerPackage advisoryGHSA-mgcc-cww5-fp2q
Go JOSE: DoS when parsing JWKs that contain RSA keys
osv.dev

References

Freshness

Last verified in this catalog Oct 27, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

Go Vulnerability DatabaseOct 28, 2026
GitHub Advisory DatabaseOct 28, 2026
OpenSSF OSV / OSV ScannerOct 28, 2026
GitLab Advisory DatabaseOct 28, 2026
CVE.orgOct 27, 2026

Priority score

12/100

Evidence confidence: High

Several independent sources name this vulnerability.

Confirmed exploitation0/30
EPSS probability1/20
CVSS severity11/15
Public exploit0/10
Internet exposure0/10
Product prevalence0/5
Detection0/5
Threat research0/5

Decision signals

Four separate signals — do not infer one from another.

High

CVSS severity
7.5 v3.1
Technical impact. Separate from exploitation likelihood.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS probability
0.37% · p30.29%
Estimated probability of exploitation within 30 days (FIRST).
Known exploitation
No verified KEV listing
Evidence from CISA KEV or VulnCheck KEV only — not from EPSS alone.
Patch availability
Version ranges on file
Affected version ranges suggest a fixed boundary. Verify against the vendor advisory for your release.

Stacks

Weakness

CWE-407 MITRE definition
CWE-770
Allocation of Resources Without Limits or Throttling
MITRE definition

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