CVE-2026-104635

HIGHPre-NVD 8.28.2
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.2Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

Uncontrolled Recursion vulnerability in Protobuf.JSON.Decode in elixir-protobuf protobuf allows an unauthenticated remote attacker to crash the decoding process via a deeply nested JSON document. Any application that decodes attacker-supplied JSON with Protobuf.JSON.decode/3, Protobuf.JSON.decode!/3, or Protobuf.JSON.from_decoded/3 into a schema that contains a self-referential or cyclic message type is affected.

In lib/protobuf/json/decode.ex, the embedded-message clause of decode_singular/3 recurses into internal_from_json_data/3 once per nesting level without incrementing or checking the decoder's depth counter. The depth guard increase_depth_and_maybe_throw/1 covers only the Google.Protobuf.ListValue and Google.Protobuf.Struct clauses, so the recursion_limit option has no effect on user-defined message types. Each nesting level allocates a stack frame and heap objects, and a sufficiently deep document exhausts the memory of the decoding process. Confidentiality and integrity are not affected.

This issue affects protobuf: from 0.8.0 before 0.17.1.

CVSS v3
8.2
EG Score
8.2HIGHlow confidence
EG Risk
41
EG Risk 41/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity82% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.4%
EPSS %ILE
30th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

October 9, 2026

Last Modified

October 9, 2026

Advisory Details (4)

Auto-updated Oct 9, 2026
🔬 Proof of concept available. No fix on record yet. Sources: github, github_commit.
github_commit

commit b0a1d4eaffaf (elixir-protobuf/protobuf)

Fix landed in elixir-protobuf/protobuf commit b0a1d4eaffaf — awaiting tagged release

https://github.com/elixir-protobuf/protobuf/commit/b0a1d4eaffaf50012fa71a8e931a47cf252d0370
generic🟡 PoC Available

OSV - Open Source Vulnerabilities

https://osv.dev/vulnerability/EEF-CVE-2026-104635
generic🟡 PoC Available

CVE-2026-104635

https://cna.erlef.org/cves/CVE-2026-104635.html
githubMentions a patch (unverified)🟡 PoC Available

Unbounded recursion in Protobuf.JSON decoding of user-defined self-referential messages · Advisory · elixir-protobuf/protobuf · GitHub

https://github.com/elixir-protobuf/protobuf/security/advisories/GHSA-m497-c2h9-rvw6

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 4× in last 7d / 4× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-09 20:06 UTCEPSS rescore
  2. 2026-10-09 09:30 UTCEG score recompute
  3. 2026-10-09 08:35 UTCEG score recompute
  4. 2026-10-09 08:33 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-104635?
CVE-2026-104635 is a high vulnerability published on October 9, 2026. Uncontrolled Recursion vulnerability in Protobuf.JSON.Decode in elixir-protobuf protobuf allows an unauthenticated remote attacker to crash the decoding process via a deeply nested JSON document. Any application that decodes attacker-supplied JSON with Protobuf.JSON.decode/3,…
When was CVE-2026-104635 disclosed?
CVE-2026-104635 was first published on October 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-104635 actively exploited?
CVE-2026-104635 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (30th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-104635?
CVE-2026-104635 has a CVSS base score of 8.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-104635?
No fix for CVE-2026-104635 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-104635

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