vulnerability / NVI-00008858 / Revision 2
Go JOSE: DoS when parsing JWKs that contain RSA keys
GitHub lists this reviewed advisory for github.com/go-jose/go-jose/v4, github.com/go-jose/go-jose/v3. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
7.5 HIGH (3.1)
security-advisories@github.com severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/go-jose/go-jose/v4
source listed<= 4.1.5
### 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 `crypto/rsa.PrivateKey.Validate()`. 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. ```go package main import ( "encoding/base64" "encoding/json" "fmt" "math/big" "time" "github.com/go-jose/go-jose/v4" ) func main() { // The RSA parameters can be complete junk. The CPU cost is in validating them. primeBits := 16384 p := new(big.Int).Lsh(big.NewInt(1), uint(primeBits-1)) p.SetBit(p, 0, 1) n := new(big.Int).Lsh(big.NewInt(1), 2048) e := big.NewInt(65537) d := big.NewInt(3) q := big.NewInt(3) jwk := map[string]string{ "kty": "RSA", "n": base64.RawURLEncoding.EncodeToString(n.Bytes()), "e": base64.RawURLEncoding.Enc
github.com/go-jose/go-jose/v3
source listed<= 3.0.5
### 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 `crypto/rsa.PrivateKey.Validate()`. 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. ```go package main import ( "encoding/base64" "encoding/json" "fmt" "math/big" "time" "github.com/go-jose/go-jose/v4" ) func main() { // The RSA parameters can be complete junk. The CPU cost is in validating them. primeBits := 16384 p := new(big.Int).Lsh(big.NewInt(1), uint(primeBits-1)) p.SetBit(p, 0, 1) n := new(big.Int).Lsh(big.NewInt(1), 2048) e := big.NewInt(65537) d := big.NewInt(3) q := big.NewInt(3) jwk := map[string]string{ "kty": "RSA", "n": base64.RawURLEncoding.EncodeToString(n.Bytes()), "e": base64.RawURLEncoding.Enc
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-mgcc-cww5-fp2q ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-116587 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.