CVE-2026-18503

LOWPre-NVD 2.42.4
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This low-severity CVE scores 2.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1% (2nd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-55630 (ENISA EUVD) · GHSA-2345-wr3r-cxf2 (GitHub Security Advisories)Source: ENISA EUVD

2.4EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • 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
2.4
EG Score
2.4LOWmedium confidence
EG Risk
11
EG Risk 11/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity24% × 45%
Impact severity (EG Severity): CVSS 2.4 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.1%
EPSS %ILE
2nd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (2.4): severity, escalated by confirmed exploitation. This CVE's 2.4 is its impact severity (EG Severity), not escalated.

EG Severity
2.4 LOWCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.1% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track 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). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 10, 2026

Last Modified

November 10, 2026

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 up to 8.0.1+dfsg-1: fixed in 8.0.1+dfsg-1
—
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 ... 8.0.1+dfsg-1 (32 versions)
  • every version on: no fix on record
—
python3.113.11.2-6 ... 3.11.2-6+deb12u8 (9 versions)
  • every version up to 3.11.2-6+deb12u9: fixed in 3.11.2-6+deb12u9
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.19+dfsg-2 ... 8.0.1+dfsg-1 (14 versions)
  • every version on: no fix on record
—
python3.133.13.11-1 ... 3.13.9-1 (15 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 12× in last 7d / 38× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 167 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 67 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  2. 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  3. 2026-11-11 08:32 UTCEchelonGraph re-scored
  4. 2026-11-11 08:32 UTCVendor advisory
  5. 2026-11-11 08:31 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  6. 2026-11-10 16:42 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  7. 2026-11-10 13:32 UTCEchelonGraph re-scored
  8. 2026-11-10 13:32 UTCVendor advisory
  9. 2026-11-10 13:32 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  10. 2026-11-10 12:47 UTCEchelonGraph re-scored
  11. 2026-11-10 12:47 UTCVendor advisory
  12. 2026-11-10 12:47 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  13. 2026-11-08 16:38 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  14. 2026-11-07 16:38 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  15. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  16. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  17. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  18. 2026-11-03 16:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  19. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  20. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  21. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  22. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  23. 2026-10-29 18:21 UTCEchelonGraph re-scored
  24. 2026-10-29 18:21 UTCVendor advisory
  25. 2026-10-29 18:21 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
Show 75 more
  1. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  4. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  5. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  6. 2026-10-25 14:45 UTCEchelonGraph re-scored
  7. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  8. 2026-10-23 20:32 UTCEchelonGraph re-scored
  9. 2026-10-23 20:32 UTCVendor advisory
  10. 2026-10-23 20:32 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  11. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  13. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  14. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  15. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  16. 2026-10-18 03:58 UTCEchelonGraph re-scored
  17. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  18. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  19. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  20. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  21. 2026-10-14 01:27 UTCEchelonGraph re-scored
  22. 2026-10-14 01:27 UTCVendor advisory
  23. 2026-10-14 01:27 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  24. 2026-10-14 00:40 UTCEchelonGraph re-scored
  25. 2026-10-14 00:40 UTCVendor advisory
  26. 2026-10-14 00:39 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  27. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  28. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  29. 2026-10-12 16:27 UTCEchelonGraph re-scored
  30. 2026-10-11 20:07 UTCEchelonGraph re-scored
  31. 2026-10-11 17:20 UTCEchelonGraph re-scored
  32. 2026-10-11 14:52 UTCEchelonGraph re-scored
  33. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  34. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  35. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  36. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  37. 2026-10-07 05:32 UTCEchelonGraph re-scored
  38. 2026-10-07 05:32 UTCVendor advisory
  39. 2026-10-07 05:32 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  40. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  41. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  42. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  43. 2026-10-04 04:26 UTCEchelonGraph re-scored
  44. 2026-10-04 04:26 UTCVendor advisory
  45. 2026-10-04 04:26 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  46. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  47. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  48. 2026-09-30 22:36 UTCEchelonGraph re-scored
  49. 2026-09-30 22:36 UTCVendor advisory
  50. 2026-09-30 22:36 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  51. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  52. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  53. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  54. 2026-09-27 12:46 UTCEchelonGraph re-scored
  55. 2026-09-27 12:46 UTCVendor advisory
  56. 2026-09-27 12:46 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  57. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  58. 2026-09-24 11:25 UTCEchelonGraph re-scored
  59. 2026-09-24 11:25 UTCVendor advisory
  60. 2026-09-24 11:25 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  61. 2026-09-21 11:10 UTCEchelonGraph re-scored
  62. 2026-09-21 11:10 UTCVendor advisory
  63. 2026-09-21 11:10 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  64. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  65. 2026-09-18 06:49 UTCEchelonGraph re-scored
  66. 2026-09-18 06:49 UTCVendor advisory
  67. 2026-09-18 06:49 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  68. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  69. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  70. 2026-09-15 06:34 UTCEchelonGraph re-scored
  71. 2026-09-15 06:34 UTCVendor advisory
  72. 2026-09-15 06:34 UTCGHSA enrichmentGHSA-2345-wr3r-cxf2 · GitHub severity LOW
  73. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  74. 2026-09-12 06:19 UTCEchelonGraph re-scored
  75. 2026-09-12 06:19 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-18503?
CVE-2026-18503 is a low-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-18503 published?
The CVE record for CVE-2026-18503 was published on August 10, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 10, 2026; the record at its source may have been updated since.
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 (2nd 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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