CVE-2020-15049

CRITICALNVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.9 under NVD CVSS v3. EPSS exploit probability: 15.7%, top 5% 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
9.9
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 6%CVSS: 9.9Exploit: NoneExposed: 0

A fix is available — apply it.

An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a Content-Length header containing "+\ "-" or an uncommon shell whitespace character prefix to the length field-value.

CVSS v3
9.9
EG Score
9.9(medium)
EPSS
92.1%
KEV
Not listed

Published

June 30, 2020

Last Modified

November 21, 2024

Advisory Details (7)

Auto-updated Jul 7, 2026
Patch available. Sources: github.
generic

[SECURITY] [DSA 4732-1] squid security update

https://www.debian.org/security/2020/dsa-4732
generic

NetApp Product Security

https://security.netapp.com/advisory/ntap-20210312-0001/
generic

[SECURITY] Fedora 31 Update: squid-4.12-1.fc31 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3RG5FGSTCAYVIJPJHIY3MRZ7NFT6HDO7/
generic Patch Available

[SECURITY] [DLA 2394-1] squid3 security update

https://lists.debian.org/debian-lts-announce/2020/10/msg00005.html
github Patch Available

SQUID-2020:7 Cache Poisoning Issue in HTTP Request processing · Advisory · squid-cache/squid · GitHub

https://github.com/squid-cache/squid/security/advisories/GHSA-qf3v-rc95-96j5
generic

squid : Optimising Web Delivery

http://www.squid-cache.org/Versions/v5/changesets/squid-5-485c9a7bb1bba88754e07ad0094647ea57a6eb8d.patch
generic

squid : Optimising Web Delivery

http://www.squid-cache.org/Versions/v4/changesets/squid-4-ea12a34d338b962707d5078d6d1fc7c6eb119a22.patch

Vendor Advisories for CVE-2020-15049(1)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntusquidclient (3.5.12-1ubuntu7.15) @ xenial2026-05-27ubuntu
ubuntusquidclient (4.10-1ubuntu1.3) @ focal2026-05-27ubuntu
redhatsquid:4-8030020200828070549.30b713e62020-11-04redhat
redhatsquid-7:3.5.20-17.el7_9.42020-09-30redhat

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.

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 8× in last 7d / 46× 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. 2026-07-11 08:24 UTCEPSS rescore
  2. 2026-07-09 19:06 UTCEPSS rescore
  3. 2026-07-08 15:11 UTCEPSS rescore
  4. 2026-07-07 13:43 UTCEPSS rescore
  5. 2026-07-06 16:25 UTCEPSS rescore
  6. 2026-07-06 16:25 UTCEPSS rescore
  7. 2026-07-06 02:20 UTCEPSS rescore
  8. 2026-07-05 02:27 UTCEPSS rescore
  9. 2026-07-04 06:28 UTCEPSS rescore
  10. 2026-07-01 16:01 UTCOSV refresh
  11. 2026-07-01 15:03 UTCEPSS rescore
  12. 2026-07-01 15:03 UTCEPSS rescore
  13. 2026-06-30 23:20 UTCEPSS rescore
  14. 2026-06-30 23:20 UTCEPSS rescore
  15. 2026-06-29 14:04 UTCEPSS rescore
  16. 2026-06-29 14:04 UTCEPSS rescore
  17. 2026-06-28 04:54 UTCEPSS rescore
  18. 2026-06-28 04:54 UTCEPSS rescore
  19. 2026-06-27 03:06 UTCEPSS rescore
  20. 2026-06-25 13:47 UTCEPSS rescore
  21. 2026-06-25 13:47 UTCEPSS rescore
  22. 2026-06-24 14:03 UTCEPSS rescore
  23. 2026-06-24 14:03 UTCEPSS rescore
  24. 2026-06-23 21:31 UTCEPSS rescore
  25. 2026-06-23 21:31 UTCEPSS rescore
Show 47 more
  1. 2026-06-22 14:23 UTCEPSS rescore
  2. 2026-06-22 14:23 UTCEPSS rescore
  3. 2026-06-21 14:54 UTCEPSS rescore
  4. 2026-06-21 14:54 UTCEPSS rescore
  5. 2026-06-21 01:57 UTCEPSS rescore
  6. 2026-06-21 01:57 UTCEPSS rescore
  7. 2026-06-19 19:23 UTCEPSS rescore
  8. 2026-06-19 19:23 UTCEPSS rescore
  9. 2026-06-18 17:50 UTCEPSS rescore
  10. 2026-06-18 17:50 UTCEPSS rescore
  11. 2026-06-17 17:50 UTCEPSS rescore
  12. 2026-06-17 17:50 UTCEPSS rescore
  13. 2026-06-16 17:50 UTCEPSS rescore
  14. 2026-06-16 17:50 UTCEPSS rescore
  15. 2026-06-15 17:46 UTCEPSS rescore
  16. 2026-06-14 23:15 UTCEPSS rescore
  17. 2026-06-14 23:15 UTCEPSS rescore
  18. 2026-06-14 00:13 UTCOSV refresh
  19. 2026-06-13 22:58 UTCEPSS rescore
  20. 2026-06-13 22:58 UTCEPSS rescore
  21. 2026-06-12 23:09 UTCEPSS rescore
  22. 2026-06-11 13:58 UTCEPSS rescore
  23. 2026-06-10 22:16 UTCEPSS rescore
  24. 2026-06-10 22:16 UTCEPSS rescore
  25. 2026-06-10 13:20 UTCEPSS rescore
  26. 2026-06-07 15:23 UTCEPSS rescore
  27. 2026-06-07 15:23 UTCEPSS rescore
  28. 2026-06-05 22:45 UTCEPSS rescore
  29. 2026-06-05 22:45 UTCEPSS rescore
  30. 2026-06-04 13:10 UTCEPSS rescore
  31. 2026-06-04 13:10 UTCEPSS rescore
  32. 2026-06-02 20:11 UTCEPSS rescore
  33. 2026-06-02 20:11 UTCEPSS rescore
  34. 2026-06-01 13:50 UTCEPSS rescore
  35. 2026-05-31 22:29 UTCEPSS rescore
  36. 2026-05-31 22:29 UTCEPSS rescore
  37. 2026-05-31 00:15 UTCEPSS rescore
  38. 2026-05-31 00:14 UTCEPSS rescore
  39. 2026-05-29 13:42 UTCEPSS rescore
  40. 2026-05-29 13:42 UTCEPSS rescore
  41. 2026-05-28 13:43 UTCEPSS rescore
  42. 2026-05-28 13:43 UTCEPSS rescore
  43. 2026-05-27 13:39 UTCEPSS rescore
  44. 2026-05-27 01:46 UTCEG score recompute
  45. 2026-05-27 01:46 UTCVendor advisory
  46. 2026-05-26 13:42 UTCEPSS rescore
  47. 2026-05-26 13:42 UTCEPSS rescore

Frequently asked(5)

What is CVE-2020-15049?
CVE-2020-15049 is a critical vulnerability published on June 30, 2020. An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a Content-Length header containing "+\ "-" or an uncommon shell whitespace…
When was CVE-2020-15049 disclosed?
CVE-2020-15049 was first published in the National Vulnerability Database on June 30, 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-2020-15049 actively exploited?
CVE-2020-15049 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 92.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-15049?
CVE-2020-15049 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2020-15049?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-15049, 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.

Dependency Blast Radius

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