CVE-2026-18503

LOWPre-NVD 2.42.4—
EchelonGraph scoreMEDIUM confidence

This low-severity CVE scores 2.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1% (1st percentile of EPSS-scored CVEs). 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
Trending — 4 sources updated this week
2.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 2.4Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing and consume significant CPU when applications pass unbounded input to csv.Sniffer.sniff().

CVSS v3
2.4
EG Score
2.4LOWmedium confidence
EG Risk
11
EG Risk 11/100CISA 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
Severity24% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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

August 10, 2026

Last Modified

August 18, 2026

References (9)

Vendor Advisories for CVE-2026-18503(7)

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

Patch Availability(5)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatpython3-12-main-3.12.14-1.hum12026-08-21redhat
redhatpython3-11-main-3.11.16-1.hum12026-08-20redhat
redhatpython3-10-main-3.10.21-1.hum12026-08-19redhat
redhatpython3-14-main-3.14.7-1.hum12026-08-13redhat
redhatpython3-13-main-3.13.15-1.hum12026-08-13redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(8 across 3 ecosystems)
Debian:14(4)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.19+dfsg-2 ... 8.0.0+dfsg-1 (13 versions)
  • every version on: no fix on record
—
python3.133.13.11-1 ... 3.13.9-1 (8 versions)
  • every version up to 3.13.15-1: fixed in 3.13.15-1
—
python3.143.14.0-1 ... 3.14.6-1 (24 versions)
  • every version up to 3.14.7-1: fixed in 3.14.7-1
—
python3.153.15.0~a8-1 ... 3.15.0~b4-1 (8 versions)
  • every version up to 3.15.0~rc1-1: fixed in 3.15.0~rc1-1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.11+dfsg-2 ... 8.0.0+dfsg-1 (31 versions)
  • every version on: no fix on record
—
python3.113.11.2-6 ... 3.11.9-1 (28 versions)
  • every version on: no fix on record
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.19+dfsg-2 ... 8.0.0+dfsg-1 (13 versions)
  • every version on: no fix on record
—
python3.133.13.11-1 ... 3.13.9-1 (14 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 47× 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.

Showing the most recent 100 of 101 total refreshes for this CVE.

  1. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 04:26 UTCEG score recompute
  3. 2026-10-04 04:26 UTCVendor advisory
  4. 2026-10-04 04:26 UTCGHSA enrichment
  5. 2026-10-03 14:25 UTCEPSS rescore
  6. 2026-10-01 19:49 UTCEPSS rescore
  7. 2026-09-30 22:36 UTCEG score recompute
  8. 2026-09-30 22:36 UTCVendor advisory
  9. 2026-09-30 22:36 UTCGHSA enrichment
  10. 2026-09-30 15:02 UTCEPSS rescore
  11. 2026-09-29 15:20 UTCEPSS rescore
  12. 2026-09-27 13:47 UTCEPSS rescore
  13. 2026-09-27 12:46 UTCEG score recompute
  14. 2026-09-27 12:46 UTCVendor advisory
  15. 2026-09-27 12:46 UTCGHSA enrichment
  16. 2026-09-26 15:58 UTCEPSS rescore
  17. 2026-09-24 11:25 UTCEG score recompute
  18. 2026-09-24 11:25 UTCVendor advisory
  19. 2026-09-24 11:25 UTCGHSA enrichment
  20. 2026-09-21 11:10 UTCEG score recompute
  21. 2026-09-21 11:10 UTCVendor advisory
  22. 2026-09-21 11:10 UTCGHSA enrichment
  23. 2026-09-18 19:27 UTCEPSS rescore
  24. 2026-09-18 06:49 UTCEG score recompute
  25. 2026-09-18 06:49 UTCVendor advisory
Show 75 more
  1. 2026-09-18 06:49 UTCGHSA enrichment
  2. 2026-09-16 14:07 UTCEPSS rescore
  3. 2026-09-16 05:14 UTCEPSS rescore
  4. 2026-09-15 06:34 UTCEG score recompute
  5. 2026-09-15 06:34 UTCVendor advisory
  6. 2026-09-15 06:34 UTCGHSA enrichment
  7. 2026-09-13 16:46 UTCEPSS rescore
  8. 2026-09-12 06:19 UTCEG score recompute
  9. 2026-09-12 06:19 UTCVendor advisory
  10. 2026-09-12 06:19 UTCGHSA enrichment
  11. 2026-09-11 14:52 UTCEPSS rescore
  12. 2026-09-11 09:36 UTCEPSS rescore
  13. 2026-09-10 09:34 UTCEPSS rescore
  14. 2026-09-09 05:51 UTCEG score recompute
  15. 2026-09-09 05:51 UTCVendor advisory
  16. 2026-09-09 05:51 UTCGHSA enrichment
  17. 2026-09-08 22:00 UTCEPSS rescore
  18. 2026-09-07 16:01 UTCEPSS rescore
  19. 2026-09-06 13:47 UTCEPSS rescore
  20. 2026-09-06 02:46 UTCEG score recompute
  21. 2026-09-06 02:46 UTCVendor advisory
  22. 2026-09-06 02:46 UTCGHSA enrichment
  23. 2026-09-04 05:06 UTCEPSS rescore
  24. 2026-09-03 02:31 UTCEG score recompute
  25. 2026-09-03 02:31 UTCVendor advisory
  26. 2026-09-03 02:31 UTCGHSA enrichment
  27. 2026-09-02 14:11 UTCEPSS rescore
  28. 2026-09-01 13:53 UTCEPSS rescore
  29. 2026-09-01 04:39 UTCEPSS rescore
  30. 2026-08-30 20:00 UTCEG score recompute
  31. 2026-08-30 20:00 UTCVendor advisory
  32. 2026-08-30 20:00 UTCGHSA enrichment
  33. 2026-08-30 19:17 UTCEPSS rescore
  34. 2026-08-28 21:41 UTCEPSS rescore
  35. 2026-08-27 19:43 UTCEG score recompute
  36. 2026-08-27 19:43 UTCVendor advisory
  37. 2026-08-27 19:43 UTCGHSA enrichment
  38. 2026-08-27 14:25 UTCEPSS rescore
  39. 2026-08-26 14:46 UTCEPSS rescore
  40. 2026-08-25 13:48 UTCEPSS rescore
  41. 2026-08-24 17:29 UTCEG score recompute
  42. 2026-08-24 17:29 UTCVendor advisory
  43. 2026-08-24 17:29 UTCGHSA enrichment
  44. 2026-08-21 23:49 UTCEPSS rescore
  45. 2026-08-21 15:48 UTCEG score recompute
  46. 2026-08-21 15:48 UTCVendor advisory
  47. 2026-08-21 15:48 UTCGHSA enrichment
  48. 2026-08-20 22:55 UTCEPSS rescore
  49. 2026-08-19 17:03 UTCEPSS rescore
  50. 2026-08-18 15:33 UTCEG score recompute
  51. 2026-08-18 15:33 UTCGHSA enrichment
  52. 2026-08-18 13:48 UTCEPSS rescore
  53. 2026-08-17 13:47 UTCEPSS rescore
  54. 2026-08-16 14:56 UTCEPSS rescore
  55. 2026-08-16 02:14 UTCEPSS rescore
  56. 2026-08-16 01:38 UTCEG score recompute
  57. 2026-08-16 01:38 UTCGHSA enrichment
  58. 2026-08-15 01:30 UTCEPSS rescore
  59. 2026-08-13 22:00 UTCEPSS rescore
  60. 2026-08-13 01:23 UTCEG score recompute
  61. 2026-08-13 01:23 UTCGHSA enrichment
  62. 2026-08-13 00:41 UTCEG score recompute
  63. 2026-08-13 00:41 UTCGHSA enrichment
  64. 2026-08-12 13:50 UTCEPSS rescore
  65. 2026-08-12 01:20 UTCEG score recompute
  66. 2026-08-12 01:20 UTCGHSA enrichment
  67. 2026-08-12 00:40 UTCEG score recompute
  68. 2026-08-12 00:40 UTCGHSA enrichment
  69. 2026-08-11 13:42 UTCEPSS rescore
  70. 2026-08-10 18:24 UTCEG score recompute
  71. 2026-08-10 18:24 UTCGHSA enrichment
  72. 2026-08-10 18:15 UTCEG score recompute
  73. 2026-08-10 18:15 UTCGHSA enrichment
  74. 2026-08-10 14:29 UTCEG score recompute
  75. 2026-08-10 14:06 UTCEG score recompute

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-18503?
CVE-2026-18503 is a low vulnerability published on August 10, 2026. Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing and consume significant CPU when applications pass unbounded input to csv.Sniffer.sniff().
When was CVE-2026-18503 disclosed?
CVE-2026-18503 was first published on August 10, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18503 actively exploited?
CVE-2026-18503 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18503?
CVE-2026-18503 has a CVSS base score of 2.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-18503?
A fix for CVE-2026-18503 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-18503 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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