CVE-2026-65631
erlang-jose RSA JWK parsing attempts to factor an attacker-controlled modulus, enabling CPU-exhaustion denial of service
- Published
- Updated
- Reserved
- Assigned by
- EEF
Description
Inefficient Algorithmic Complexity in erlang-jose allows an unauthenticated remote attacker to cause a CPU-exhaustion denial of service by submitting a crafted RSA JSON Web Key. When an application parses an untrusted JWK through the public jose_jwk:from_binary/1 or jose_jwk:from_map/1 API (or the Elixir wrappers JOSE.JWK.from_binary/1 and JOSE.JWK.from_map/1), an RSA private key that supplies d, e, and n but omits all Chinese Remainder Theorem parameters (p, q, dp, dq, qi) is routed into convert_sfm_to_crt/1, which tries to recover the missing primes by factoring the modulus. The three integers are read straight from the base64url input and are never validated as a real RSA key. When the modulus cannot be split into two factors (for example, when it is itself prime), the search loop convert_sfm_to_crt_find_p/6 performs a modular exponentiation over the attacker-sized modulus on every iteration and never succeeds. A single request of a few hundred bytes forces close to one CPU-second of work before an internal one-second watchdog kills the worker, and a larger modulus raises the cost further. By flooding such requests an attacker can saturate every scheduler and deny service, without credentials, a valid RSA key, or any special configuration. This issue affects jose: from 1.7.7 before 1.11.13.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| EEFCNA (assigner) | 4.0 | Medium6.9 | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| NVDNVD · Deferred | 4.0 | Medium6.9 | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.24% · top 86% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Weakness
Affected products
- affected 1.7.7 – < 1.11.13
- affected d19e1ba68d88c68d29aa942be2573a22dbafca1f – < bfd336c0062bff93e65d08c22361897e96afd956
References (5)
- https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-3m45-vrpj-xmrq (opens in a new tab)vendor-advisoryrelated
- EEF CNA record for CVE-2026-65631 (opens in a new tab)related
- OSV record EEF-CVE-2026-65631 (opens in a new tab)related
- Introducing commit d19e1ba in potatosalad/erlang-jose (opens in a new tab)related
- Fix commit bfd336c in potatosalad/erlang-jose (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-65631)Record last updated .