CVE-2026-65628 — Infinite recursion (CPU denial-of-service) in JOSE.JWK.shared_secret/2 on mismatched key types
jose_jwk:shared_secret/2 (exposed in Elixir as JOSE.JWK.shared_secret/2) derives an ECDH shared secret from two JWKs. Its first function clause only matches when both JWKs carry the same key type (kty) module, and its fallback clause re-invokes itself as shared_secret(from(YourJWK), from(MyJWK)). Because from/1 returns an already-parsed jose_jwk record unchanged, passing two JWKs whose key types differ (for example an EC key and an RSA key) makes the fallback clause re-enter with identical arguments, producing an unbounded tail-recursive loop that never returns and never crashes. An application that derives a shared secret from an externally supplied peer public key without first checking that the peer key's type and curve match its own key can be driven into this loop by an attacker-controlled JWK, pinning an Erlang scheduler at 100% CPU. Repeated requests exhaust the available schedulers, resulting in a denial of service. This issue affects jose: from 1.5.0 before 1.11.13.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+0
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Potatosalad Jose).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Potatosalad | Jose | ≥ 1.5.0 and < 1.11.13≥ 7b80b9f55b9898e1a6901ce136061b241b021d7c and < 26182a7de63b91550035d3f08741f7d17f1f675a | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.9 | CVSS 4.0 | Medium | — | — | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db via NIST National Vulnerability Database |
| 5.9 | CVSS 4.0 | Medium | — | — | EEF via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:L/AC:L/AT:P/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 (score shown at the top: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Received → Deferred
- Affected products added · potatosalad/jose
- Record published
- CVSS changed · 5.9
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 26, 2026 – Oct 26, 2026
- 1× Official description updated · Oct 26, 2026 – Oct 26, 2026
References
5 on the record
- github.com/potatosalad/erlang-jose/commit/26182a7de63b91550035d3f08741f7d17f1f67
- cna.erlef.org/cves/CVE-2026-65628.html
- github.com/potatosalad/erlang-jose/commit/7b80b9f55b9898e1a6901ce136061b241b021d
- github.com/potatosalad/erlang-jose/security/advisories/GHSA-fpj2-9h59-32pp
- osv.dev/vulnerability/EEF-CVE-2026-65628
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-65632 ECDSA signature length is not validated in jose, allowing signature malleability 19h
- Medium CVE-2026-65626 Bleichenbacher padding oracle in RSAES-PKCS1-v1_5 decryption in jose 19h
- Medium CVE-2026-65627 Decompression bomb via unbounded zlib:inflate in jose_jwe_zip:uncompress/2 19h
- High CVE-2026-65629 Weak PBKDF2 parameters for password-encrypted private-key export in jose 19h
- Medium CVE-2026-65631 erlang-jose RSA JWK parsing attempts to factor an attacker-controlled modulus, enabling CPU-exhaustion denial of service 19h
- Medium CVE-2026-65630 Timing side-channel in pure-Erlang X25519 scalar multiplication leaks the private key in jose 19h
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-65628 is "Infinite recursion (CPU denial-of-service) in JOSE.JWK.shared_secret/2 on mismatched key types", rated Medium. It affects Jose (Potatosalad); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.9 describes technical severity. EPSS 0.14% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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