CVE-2026-49838

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 73% of all CVEs by exploit prediction. 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: epss, secondary
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: None knownExposed: 0

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

GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Prior to version 4.7.0, GoBGP accepts a zero-length AS_PATH during UPDATE decoding and later panics while validating that attribute for a confederation eBGP peer. The vulnerable path is in the BGP UPDATE validator: a malformed UPDATE that should be rejected as a malformed AS_PATH instead reaches an unchecked p.Value[0] access, allowing a configured confederation eBGP peer to trigger a denial of service. Version 4.7.0 patches the issue.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: 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
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

July 9, 2026

Last Modified

September 16, 2026

Advisory Details (2)

Auto-updated Sep 10, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit

commit 4a319a6c2563 (osrg/gobgp)

Fix landed in osrg/gobgp commit 4a319a6c2563 — awaiting tagged release

https://github.com/osrg/gobgp/commit/4a319a6c25630fb3cdbda3e9ccfe56e702bdaaa0
github Patch Available🟡 PoC Available

GoBGP confed validation panics on empty AS_PATH attribute · Advisory · osrg/gobgp · GitHub

https://github.com/osrg/gobgp/security/advisories/GHSA-frrj-87jh-2772

Vendor Advisories for CVE-2026-49838(1)

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

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
gobgp2.25.0-2 ... 4.7.0-1 (30 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
gobgp3.10.0-1 ... 4.8.0-2~exp1 (27 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
gobgp3.36.0-2 ... 4.8.0-2~exp1 (12 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
gobgp3.36.0-2 ... 4.7.0-1~bpo13+1 (9 versions)4.7.0-1—
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/osrg/gobgp/v4—4.7.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 12× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 05:26 UTCEG score recompute
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-16 13:47 UTCEG score recompute
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-14 11:11 UTCEG score recompute
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-13 08:16 UTCEG score recompute
  9. 2026-09-11 21:24 UTCEG score recompute
  10. 2026-09-11 20:34 UTCEG score recompute
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-10 22:20 UTCEG score recompute
  13. 2026-07-30 23:32 UTCEG score recompute
  14. 2026-07-26 12:14 UTCEG score recompute
  15. 2026-07-23 03:18 UTCEG score recompute
  16. 2026-07-09 23:46 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-49838?
CVE-2026-49838 is a medium vulnerability published on July 9, 2026. GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Prior to version 4.7.0, GoBGP accepts a zero-length ASPATH during UPDATE decoding and later panics while validating that attribute for a confederation eBGP peer. The vulnerable path is in the BGP…
When was CVE-2026-49838 disclosed?
CVE-2026-49838 was first published in the National Vulnerability Database on July 9, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49838 actively exploited?
CVE-2026-49838 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 73.2% of all scored CVEs.
What is the CVSS score of CVE-2026-49838?
CVE-2026-49838 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-49838?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49838, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-49838

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