CVE-2026-18738

MEDIUMPre-NVD 4.74.7—
EchelonGraph scoreHIGH confidence

Score 4.7 from GitHub Security Advisory published 2026-08-03. a secondary CVSS source baseline 4.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
4.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.7Exploit: None knownExposed: 0

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

Shlink versions 5.0.0 through 5.1.5 contain a CSV formula injection vulnerability that allows unauthenticated remote attackers to plant spreadsheet formulas into exported visit data by supplying malicious values in User-Agent, Referer, or request path headers beginning with formula-triggering characters such as =, +, -, or @. Attackers can craft a single unauthenticated request against any short URL to embed DDE or WEBSERVICE formula payloads into CSV cells, which are then executed on an administrator's client machine when the exported CSV file is opened in a spreadsheet application that evaluates formulas.

CVSS v3
4.7
EG Score
4.7(high)
EG Risk
36(Track)
EG Risk 36/100SSVC: 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
Severity47% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
32%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 4, 2026

Advisory Details (3)

Auto-updated Aug 3, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

Shlink CSV Formula Injection via Visit Export CLI | Advisories | VulnCheck

https://www.vulncheck.com/advisories/shlink-csv-formula-injection-via-visit-export-cli
generic🟡 PoC Available

GitHub - theopaid/CSV-formula-injection-in-visit-exports-shlink-: Security Advisory: CSV formula injection in visit exports (shlink) · GitHub

https://github.com/theopaid/CSV-formula-injection-in-visit-exports-shlink-
generic

GitHub - shlinkio/shlink: The definitive self-hosted URL shortener · GitHub

https://github.com/shlinkio/shlink

Vendor Advisories for CVE-2026-18738(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 49× 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. 2026-08-20 00:05 UTCEG score recompute
  2. 2026-08-20 00:05 UTCGHSA enrichment
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 21:50 UTCEG score recompute
  5. 2026-08-18 21:50 UTCGHSA enrichment
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 19:36 UTCEG score recompute
  8. 2026-08-17 19:36 UTCGHSA enrichment
  9. 2026-08-17 13:47 UTCEPSS rescore
  10. 2026-08-16 17:08 UTCEG score recompute
  11. 2026-08-16 17:08 UTCGHSA enrichment
  12. 2026-08-16 14:56 UTCEPSS rescore
  13. 2026-08-16 02:14 UTCEPSS rescore
  14. 2026-08-15 14:54 UTCEG score recompute
  15. 2026-08-15 14:54 UTCGHSA enrichment
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-14 12:40 UTCEG score recompute
  18. 2026-08-14 12:40 UTCGHSA enrichment
  19. 2026-08-13 22:00 UTCEPSS rescore
  20. 2026-08-13 10:26 UTCEG score recompute
  21. 2026-08-13 10:26 UTCGHSA enrichment
  22. 2026-08-12 13:50 UTCEPSS rescore
  23. 2026-08-12 08:12 UTCEG score recompute
  24. 2026-08-12 08:12 UTCGHSA enrichment
  25. 2026-08-11 13:42 UTCEPSS rescore
Show 24 more
  1. 2026-08-11 05:57 UTCEG score recompute
  2. 2026-08-11 05:57 UTCGHSA enrichment
  3. 2026-08-11 00:00 UTCEPSS rescore
  4. 2026-08-10 03:44 UTCEG score recompute
  5. 2026-08-10 03:44 UTCGHSA enrichment
  6. 2026-08-09 13:46 UTCEPSS rescore
  7. 2026-08-09 01:30 UTCEG score recompute
  8. 2026-08-09 01:30 UTCGHSA enrichment
  9. 2026-08-08 16:37 UTCEPSS rescore
  10. 2026-08-07 23:16 UTCEG score recompute
  11. 2026-08-07 23:16 UTCGHSA enrichment
  12. 2026-08-06 21:02 UTCEG score recompute
  13. 2026-08-06 21:02 UTCGHSA enrichment
  14. 2026-08-06 13:46 UTCEPSS rescore
  15. 2026-08-05 19:17 UTCEPSS rescore
  16. 2026-08-05 18:48 UTCGHSA enrichment
  17. 2026-08-04 16:34 UTCEG score recompute
  18. 2026-08-04 16:34 UTCGHSA enrichment
  19. 2026-08-04 15:38 UTCEG score recompute
  20. 2026-08-04 15:38 UTCGHSA enrichment
  21. 2026-08-04 15:10 UTCEPSS rescore
  22. 2026-08-03 21:20 UTCEG score recompute
  23. 2026-08-03 21:08 UTCEG score recompute
  24. 2026-08-03 21:08 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18738?
CVE-2026-18738 is a medium vulnerability published on August 3, 2026. Shlink versions 5.0.0 through 5.1.5 contain a CSV formula injection vulnerability that allows unauthenticated remote attackers to plant spreadsheet formulas into exported visit data by supplying malicious values in User-Agent, Referer, or request path headers beginning with formula-triggering…
When was CVE-2026-18738 disclosed?
CVE-2026-18738 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on August 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18738 actively exploited?
CVE-2026-18738 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 68.5% of all scored CVEs.
What is the CVSS score of CVE-2026-18738?
CVE-2026-18738 has a CVSS v3 base score of 4.7 (NVD).
How do I remediate CVE-2026-18738?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18738, 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

Explore the affected products and dependency analysis for CVE-2026-18738

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