CVE-2026-54638

HIGHPre-NVD 7.57.5
EchelonGraph scoreLOW confidence

This high-severity CVE scores 7.5 under the CNA's CVSS (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: cna:github_m
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 7.5Exploit: None knownExposed: 0

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

gotd/td is a T Telegram MTProto API client in Go. Prior to 0.145.1, proto.UnencryptedMessage.Decode in proto/unencrypted_message.go read attacker controlled dataLen from an unauthenticated MTProto unencrypted packet and allocated make([]byte, dataLen) before checking the remaining buffer, allowing remote unauthenticated denial of service through excessive memory allocation and CPU or garbage collection pressure. This issue is fixed in version 0.145.1.

CVSS v3
7.5
EG Score
7.5(low)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

July 28, 2026

Last Modified

July 29, 2026

Advisory Details (4)

Auto-updated Jul 28, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available

Pre-auth denial of service via unbounded memory allocation in proto.UnencryptedMessage.Decode · Advisory · gotd/td · GitHub

https://github.com/gotd/td/security/advisories/GHSA-whmm-qj9r-wvr2
github_release Patch Available

v0.145.1

Patch available: gotd/td v0.145.1

https://github.com/gotd/td/releases/tag/v0.145.1
generic🟡 PoC Available

Potential DoS via Unbounded Memory Allocation in proto.UnencryptedMessage.Decode · Issue #1711 · gotd/td · GitHub

https://github.com/gotd/td/issues/1711
github_commit Patch Available

commit 9d5d1f31ea50 (gotd/td)

Patch available: gotd/td v0.145.1 (contains commit 9d5d1f31ea50)

https://github.com/gotd/td/commit/9d5d1f31ea5022d9798d84ccce15de2e91ba6baa

Vendor Advisories for CVE-2026-54638(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 3× in last 7d / 3× 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. 2026-07-29 14:49 UTCEG score recompute
  2. 2026-07-28 23:23 UTCEG score recompute
  3. 2026-07-28 22:17 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-54638?
CVE-2026-54638 is a high vulnerability published on July 28, 2026. gotd/td is a T Telegram MTProto API client in Go. Prior to 0.145.1, proto.UnencryptedMessage.Decode in proto/unencrypted_message.go read attacker controlled dataLen from an unauthenticated MTProto unencrypted packet and allocated make([]byte, dataLen) before checking the remaining buffer, allowing…
When was CVE-2026-54638 disclosed?
CVE-2026-54638 was first published in the National Vulnerability Database on July 28, 2026, with the most recent update on July 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-54638?
CVE-2026-54638 has a CVSS v4.0 base score of 7.5 (CNA self-assessment; 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-2026-54638?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54638, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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