CVE-2019-12519

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 6.7%, top 7% 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: epss, nvd
Trending — 3 sources updated this week
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 7%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a new member to the stack. When adding a new member, there is no check to ensure that the stack won't overflow.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
51(Track)
EG Risk 51/100SSVC: 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
Severity98% × 45%
Exploitation7% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
93.2%
KEV
Not listed

Published

April 15, 2020

Last Modified

November 21, 2024

Advisory Details (6)

Auto-updated May 27, 2026
Patch available.
generic Patch Available

oss-security - [ADVISORY] SQUID-2019:12 Multiple issues in ESI Response processing

http://www.openwall.com/lists/oss-security/2020/04/23/1
generic

[SECURITY] [DSA 4682-1] squid security update

https://www.debian.org/security/2020/dsa-4682
generic

NetApp Product Security

https://security.netapp.com/advisory/ntap-20210205-0006/
generic

Squid: Multiple vulnerabilities (GLSA 202005-05) — Gentoo security

https://security.gentoo.org/glsa/202005-05
generic Patch Available

[SECURITY] [DLA 2278-1] squid3 security update

https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html
generic

squid/CVEs/CVE-2019-12519.txt · master · Jeriko One / Security · GitLab

https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12519.txt

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntusquidclient (3.5.12-1ubuntu7.11) @ xenial2026-05-27ubuntu
redhatsquid:4-8010020200429095057.c27ad7f82020-05-06redhat
redhatsquid-7:3.5.20-15.el7_8.12020-05-06redhat
redhatsquid:4-8020020200430095908.4cda2c842020-05-06redhat
redhatsquid:4-8000020200428154754.f8e95b4e2020-05-06redhat

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.

Weakness Classification(1)

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

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2019-12519?
CVE-2019-12519 is a critical vulnerability published on April 15, 2020. An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the…
When was CVE-2019-12519 disclosed?
CVE-2019-12519 was first published in the National Vulnerability Database on April 15, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2019-12519 actively exploited?
CVE-2019-12519 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 93.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2019-12519?
CVE-2019-12519 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2019-12519?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2019-12519, 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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