CVE-2026-43969

LOWNVD 3.23.2—
EchelonGraph scoreMEDIUM confidence

Score 3.2 from GitHub Security Advisory (severity: LOW) published 2026-05-11. NVD baseline CVSS 3.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
3.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 3.2Exploit: None knownExposed services: Not assessed

A fixed version is listed under Patch Availability — apply it.

Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in ninenines cowlib allows HTTP request splitting and cookie smuggling via unvalidated cookie name and value fields.

cow_cookie:cookie/1 in cowlib builds a client-side Cookie: request header from a list of name-value pairs without validating either field. An attacker who controls the cookie names or values passed to this function can inject ;, ,, CR, LF, or TAB characters into the serialized header. This enables two classes of attack: cookie smuggling within a single header (e.g. injecting ; admin=1 to introduce a phantom cookie that the receiving server treats as authentic) and HTTP request header splitting (injecting CRLF to append arbitrary headers or smuggle a complete second request against a shared upstream proxy). The decoder side (parse_cookie_name/1, parse_cookie_value/1) and setcookie/3 already validate and reject these characters; the encoder alone is missing the check.

This issue affects cowlib: from 2.9.0 before 2.21.0.

CVSS v3
3.2
EG Score
3.2LOWmedium confidence
EG Risk
14
EG Risk 14/100CISA 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
Severity32% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fixed version is listed under Patch Availability. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
10th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fixed version is listed under Patch Availability. 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

May 11, 2026

Last Modified

October 9, 2026

References (5)

Vendor Advisories for CVE-2026-43969(2)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
erlangcowlib—ghsa

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

(1 across 1 ecosystem)
Hex(1)
PackageVulnerable rangeFix by version rangeDependents
cowlib2.10.0 ... 2.9.1 (12 versions)
  • 2.9.0 on: no fix on record
  • 2.9.0 through 2.16.1: 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 / 29× 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 173 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-43969?
CVE-2026-43969 is a low vulnerability published on May 11, 2026. Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in ninenines cowlib allows HTTP request splitting and cookie smuggling via unvalidated cookie name and value fields. cowcookie:cookie/1 in cowlib builds a client-side Cookie: request header from a list of name-value pairs…
When was CVE-2026-43969 disclosed?
CVE-2026-43969 was first published on May 11, 2026, with the most recent update on October 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43969 actively exploited?
CVE-2026-43969 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-43969?
CVE-2026-43969 has a CVSS v3 base score of 3.2 (NVD).
How do I remediate CVE-2026-43969?
A fixed version for CVE-2026-43969 is listed under Patch Availability on this page: update to the version listed for your package. The vendor advisories EchelonGraph has for CVE-2026-43969 are linked in the Vendor Advisories panel on this page.

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