CVE-2026-7790

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 64% 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: cna:eef, epss
Trending — 3 sources updated this week
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: None knownExposed: 0

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

Uncontrolled Resource Consumption vulnerability in ninenines cowlib (cow_http_te module) allows Excessive Allocation.

The chunked transfer-encoding parser in cow_http_te accepts an unbounded number of hex digits in the chunk-size field. Each digit causes a bignum multiplication (Len * 16 + digit), so parsing N hex digits requires O(N²) CPU work and O(N) memory. Additionally, when input is drip-fed, the parser discards the accumulated length on each partial read and restarts from zero on resumption, raising the cost to O(N³). An unauthenticated remote attacker can exploit this by sending an HTTP/1.1 request with Transfer-Encoding: chunked and a very long chunk-size hex string to cause denial of service through CPU exhaustion and memory amplification.

This vulnerability is associated with program file src/cow_http_te.erl and program routines cow_http_te:stream_chunked/2, cow_http_te:chunked_len/4.

This issue affects cowlib: from 0.6.0 before 2.16.1.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
54(Track)
EG Risk 54/100SSVC: 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
Severity87% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

May 11, 2026

Last Modified

May 26, 2026

Advisory Details (3)

Auto-updated May 11, 2026
No patch confirmed yet.
generic

OSV - Open Source Vulnerabilities

https://osv.dev/vulnerability/EEF-CVE-2026-7790
generic

Limit length of transfer-encoding: chunked chunks · ninenines/cowlib@a4b8039 · GitHub

https://github.com/ninenines/cowlib/commit/a4b8039ce8c93ab00867ef6b7e888822c09f4369
generic

Unbounded chunk-size hex digits in cowlib cause quadratic CPU and memory DoS | Erlang Ecosystem Foundation CNA

https://cna.erlef.org/cves/CVE-2026-7790.html

Vendor Advisories for CVE-2026-7790(2)

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
erlang-cowlib1.3.0-3, 2.17.1-1, 2.17.1-2, 2.18.0-1, 2.19.0-1——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
erlang-cowlib1.3.0-3, 2.17.1-1, 2.17.1-2, 2.18.0-1, 2.19.0-1——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
erlang-cowlib1.3.0-3, 2.17.1-1, 2.17.1-2, 2.18.0-1, 2.19.0-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
erlang-cowlib1.3.0-32.17.1-1—
Hex(1)
PackageVulnerable rangeFixed inDependents
cowlib1.0.0 ... 2.9.1 (32 versions)2.16.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 67× 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 180 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-7790?
CVE-2026-7790 is a high vulnerability published on May 11, 2026. Uncontrolled Resource Consumption vulnerability in ninenines cowlib (cowhttpte module) allows Excessive Allocation. The chunked transfer-encoding parser in cowhttpte accepts an unbounded number of hex digits in the chunk-size field. Each digit causes a bignum multiplication (Len * 16 + digit), so…
When was CVE-2026-7790 disclosed?
CVE-2026-7790 was first published in the National Vulnerability Database on May 11, 2026, with the most recent update on May 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-7790 actively exploited?
CVE-2026-7790 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 64.2% of all scored CVEs.
What is the CVSS score of CVE-2026-7790?
CVE-2026-7790 has a CVSS v4.0 base score of 8.7 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-7790?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-7790, 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.

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