CVE-2023-49285

CRITICALNVD 7.59.0
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score elevated to 9.0 because EPSS predicted 88% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs) when EchelonGraph scored this CVE. NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: EPSS, NVD CVSS v3
Elevated

Also known asEUVD-2023-53278 (ENISA EUVD)Source: ENISA EUVD

9.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High exploitation likelihood — EPSS 88%
CISA-KEV: Not listedEPSS PROB: 88%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a Buffer Overread bug Squid is vulnerable to a Denial of Service attack against Squid HTTP Message processing. This bug is fixed by Squid version 6.5. Users are advised to upgrade. There are no known workarounds for this vulnerability.

CVSS v3
7.5
EG Score
9.0CRITICALhigh confidence
EG Risk
69
EG Risk 69/100

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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation88% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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
88%
EPSS %ILE
99th
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 (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is EPSS's lift toward 9.0 from its impact severity (EG Severity, CVSS 7.5 HIGH): a likelihood of exploitation, not impact.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
88% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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 low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 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 low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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)14 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's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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

December 4, 2023

Last Modified

June 17, 2026

Advisory Details (9)

Auto-updated Oct 12, 2026
Patch available. Sources: github, github_commit.
Web page

[SECURITY] Fedora 38 Update: squid-6.6-1.fc38 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/[email protected]/message/MEV66D3PAAY6K7TWDT3WZBLCPLASFJDC/
Web page

[SECURITY] Fedora 39 Update: squid-6.6-1.fc39 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/[email protected]/message/A5QASTMCUSUEW3UOMKHZJB3FTONWSRXS/
Web pageMentions a patch (unverified)

[SECURITY] [DLA 3709-1] squid security update

https://lists.debian.org/debian-lts-announce/2024/01/msg00003.html
GitHub advisoryMentions a patch (unverified)

SQUID-2023:7 Denial of Service in HTTP Message Processing · Advisory · squid-cache/squid · GitHub

https://github.com/squid-cache/squid/security/advisories/GHSA-8w9r-p88v-mmx9
GitHub commit

commit deee944f9a12 (squid-cache/squid)

Fix landed in squid-cache/squid commit deee944f9a12 — awaiting tagged release

https://github.com/squid-cache/squid/commit/deee944f9a12c9fd399ce52f3e2526bb573a9470
GitHub commit

commit 77b3fb4df0f1 (squid-cache/squid)

Fix landed in squid-cache/squid commit 77b3fb4df0f1 — awaiting tagged release

https://github.com/squid-cache/squid/commit/77b3fb4df0f126784d5fd4967c28ed40eb8d521b

Patch Availability(11)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntusquidclient (3.5.12-1ubuntu7.16+esm3) @ xenial2026-11-01ubuntu
ubuntusquidclient (4.10-1ubuntu1.9) @ focal2026-11-01ubuntu
redhatsquid-7:3.5.20-17.el7_9.102024-04-11redhat
redhatsquid-7:5.2-1.el9_0.42024-03-05redhat
redhatsquid:4-8020020240122164331.4cda2c842024-02-12redhat
redhatsquid:4-8060020231222131040.ad008a3a2024-02-12redhat
redhatsquid:4-8040020240122165847.522a0ee42024-02-12redhat
redhatsquid:4-8080020231222130009.63b345852024-01-24redhat
redhatsquid-7:5.5-6.el9_3.52024-01-08redhat
redhatsquid-7:5.5-5.el9_2.32024-01-08redhat
redhatsquid:4-8090020231207155957.a75119d52024-01-03redhat

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

(11 across 11 ecosystems)
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-r0: fixed in 6.5-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-r0: fixed in 6.5-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-r0: fixed in 6.5-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-r0: fixed in 6.5-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-r0: fixed in 6.5-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-r0: fixed in 6.5-r0
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
squid4.6-1 ... 4.6-1+deb10u8 (9 versions)
  • every version up to 4.6-1+deb10u9: fixed in 4.6-1+deb10u9
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
squid4.13-10, 4.13-10+deb11u1, 4.13-10+deb11u2
  • every version up to 4.13-10+deb11u3: fixed in 4.13-10+deb11u3
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
squid5.7-2
  • every version up to 5.7-2+deb12u1: fixed in 5.7-2+deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-1: fixed in 6.5-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
squid—
  • every version up to 6.5-1: fixed in 6.5-1
—

Weakness Classification(2)

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

Additional Vendor Advisories

(2)

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 7× in last 7d / 37× 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 v3 → 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 165 rows on record for this CVE, as 97 entries (3 repeats merged).

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. 3 repeat rows among the latest 100 are merged into the row they repeat. The 65 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 21:18 UTCEchelonGraph re-scored
  2. 2026-11-12 21:18 UTCVendor advisory
  3. 2026-11-11 18:53 UTCEchelonGraph re-scored
  4. 2026-11-11 18:53 UTCVendor advisory
  5. 2026-11-11 16:34 UTCEPSS rescoreEPSS 88% · 99th percentile
  6. 2026-11-10 16:28 UTCEchelonGraph re-scored
  7. 2026-11-10 16:28 UTCVendor advisory
  8. 2026-11-09 14:00 UTCEchelonGraph re-scored
  9. 2026-11-09 14:00 UTCVendor advisory
  10. 2026-11-08 16:35 UTCEPSS rescoreEPSS 88% · 99th percentile
  11. 2026-11-08 11:35 UTCEchelonGraph re-scored
  12. 2026-11-07 09:10 UTCEchelonGraph re-scored
  13. 2026-11-07 09:10 UTCVendor advisory
  14. 2026-11-06 06:46 UTCEchelonGraph re-scored
  15. 2026-11-06 06:46 UTCVendor advisory
  16. 2026-11-05 16:33 UTCEPSS rescoreEPSS 88% · 99th percentile
  17. 2026-11-05 04:22 UTCEchelonGraph re-scored
  18. 2026-11-05 04:22 UTCVendor advisory
  19. 2026-11-04 18:25 UTCOSV refresh
  20. 2026-11-04 16:31 UTCEPSS rescoreEPSS 88% · 99th percentile
  21. 2026-11-04 01:53 UTCEchelonGraph re-scored
  22. 2026-11-04 01:53 UTCVendor advisory
  23. 2026-11-02 23:28 UTCEchelonGraph re-scored
  24. 2026-11-02 23:28 UTCVendor advisory
  25. 2026-11-01 21:03 UTCEchelonGraph re-scored
Show 72 more
  1. 2026-11-01 21:03 UTCVendor advisory
  2. 2026-10-31 18:38 UTCEchelonGraph re-scored
  3. 2026-10-31 18:38 UTCVendor advisory
  4. 2026-10-30 16:13 UTCEchelonGraph re-scored
  5. 2026-10-30 16:13 UTCVendor advisory
  6. 2026-10-29 16:30 UTCEPSS rescoreEPSS 88% · 99th percentile
  7. 2026-10-29 13:48 UTCEchelonGraph re-scored
  8. 2026-10-29 13:48 UTCVendor advisory
  9. 2026-10-28 11:21 UTCEchelonGraph re-scored
  10. 2026-10-28 11:21 UTCVendor advisory
  11. 2026-10-27 08:29 UTCEchelonGraph re-scored
  12. 2026-10-27 08:29 UTCVendor advisory
  13. 2026-10-26 16:29 UTCEPSS rescoreEPSS 88% · 99th percentile
  14. 2026-10-26 03:54 UTCVendor advisory
  15. 2026-10-25 17:31 UTCEchelonGraph re-scored
  16. 2026-10-25 16:30 UTCEPSS rescoreEPSS 88% · 99th percentile
  17. 2026-10-25 01:30 UTCEchelonGraph re-scored
  18. 2026-10-25 01:30 UTCVendor advisory
  19. 2026-10-23 23:06 UTCEchelonGraph re-scored
  20. 2026-10-23 23:06 UTCVendor advisory
  21. 2026-10-22 20:39 UTCEchelonGraph re-scored
  22. 2026-10-22 20:39 UTCVendor advisory
  23. 2026-10-21 18:12 UTCEchelonGraph re-scored
  24. 2026-10-21 18:12 UTCVendor advisory
  25. 2026-10-21 16:29 UTCEPSS rescoreEPSS 88% · 99th percentile
  26. 2026-10-20 15:47 UTCEchelonGraph re-scored
  27. 2026-10-20 15:47 UTCVendor advisory
  28. 2026-10-19 16:29 UTCEPSS rescoreEPSS 88% · 99th percentile
  29. 2026-10-19 13:21 UTCEchelonGraph re-scored
  30. 2026-10-19 13:21 UTCVendor advisory
  31. 2026-10-18 10:57 UTCVendor advisory
  32. 2026-10-18 07:45 UTCEchelonGraph re-scored
  33. 2026-10-17 05:25 UTCEchelonGraph re-scored
  34. 2026-10-17 05:25 UTCVendor advisory
  35. 2026-10-16 03:00 UTCEchelonGraph re-scored
  36. 2026-10-16 03:00 UTCVendor advisory
  37. 2026-10-14 23:04 UTCEchelonGraph re-scored
  38. 2026-10-14 23:04 UTCVendor advisory
  39. 2026-10-14 16:30 UTCEPSS rescoreEPSS 88% · 99th percentile
  40. 2026-10-13 18:46 UTCEchelonGraph re-scored
  41. 2026-10-13 18:46 UTCVendor advisory
  42. 2026-10-12 16:19 UTCEchelonGraph re-scored
  43. 2026-10-12 16:19 UTCVendor advisory
  44. 2026-10-11 21:41 UTCEchelonGraph re-scored
  45. 2026-10-09 20:05 UTCEPSS rescoreEPSS 88% · 99th percentile
  46. 2026-09-30 19:14 UTCOSV refresh
  47. 2026-09-30 16:34 UTCEchelonGraph re-scored
  48. 2026-09-26 00:22 UTCEPSS rescoreEPSS 88% · 99th percentile
  49. 2026-09-24 14:01 UTCEPSS rescoreEPSS 88% · 99th percentile
  50. 2026-09-22 14:46 UTCEPSS rescoreEPSS 88% · 99th percentile
  51. 2026-09-21 20:31 UTCEPSS rescoreEPSS 88% · 99th percentile
  52. 2026-09-20 20:14 UTCEPSS rescoreEPSS 88% · 99th percentile
  53. 2026-09-17 19:25 UTCEPSS rescoreEPSS 88% · 99th percentile
  54. 2026-09-16 14:06 UTCEPSS rescoreEPSS 88% · 99th percentile
  55. 2026-09-15 03:08 UTCEPSS rescoreEPSS 88% · 99th percentile
  56. 2026-09-12 02:10 UTCOSV refresh
  57. 2026-09-11 09:34 UTCEPSS rescoreEPSS 88% · 99th percentile
  58. 2026-09-07 15:59 UTCEPSS rescoreEPSS 88% · 99th percentile
  59. 2026-09-06 13:45 UTCEPSS rescoreEPSS 88% · 99th percentile
  60. 2026-09-05 15:26 UTCEPSS rescoreEPSS 88% · 99th percentile
  61. 2026-09-04 05:04 UTCEPSS rescoreEPSS 89% · 99th percentile
  62. 2026-08-30 19:15 UTCEPSS rescoreEPSS 89% · 99th percentile
  63. 2026-08-28 21:39 UTCEPSS rescoreEPSS 89% · 99th percentile
  64. 2026-08-27 14:23 UTCEPSS rescoreEPSS 89% · 99th percentile
  65. 2026-08-26 14:44 UTCEPSS rescoreEPSS 89% · 99th percentile
  66. 2026-08-25 13:46 UTCEPSS rescoreEPSS 89% · 99th percentile
  67. 2026-08-24 14:14 UTCEPSS rescoreEPSS 89% · 99th percentile
  68. 2026-08-24 07:57 UTCOSV refresh
  69. 2026-08-21 23:47 UTCEPSS rescoreEPSS 89% · 99th percentile
  70. 2026-08-15 01:28 UTCEPSS rescoreEPSS 89% · 99th percentile
  71. 2026-08-12 13:49 UTCEPSS rescoreEPSS 89% · 99th percentile
  72. 2026-08-08 16:35 UTCEPSS rescoreEPSS 89% · 99th percentile

Frequently asked(5)

What is CVE-2023-49285?
CVE-2023-49285 is a critical-severity vulnerability; its CVE record was published on December 4, 2023. Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a Buffer Overread bug Squid is vulnerable to a Denial of Service attack against Squid HTTP Message processing. This bug is fixed by Squid version 6.5. Users are advised to upgrade. There are no known workarounds for…
When was the CVE record for CVE-2023-49285 published?
The CVE record for CVE-2023-49285 was published on December 4, 2023. 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 June 17, 2026; the record at its source may have been updated since.
Is CVE-2023-49285 actively exploited?
CVE-2023-49285 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 88% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-49285?
CVE-2023-49285 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + FIRST EPSS into a combined EG score of 9.0 (CRITICAL).
How do I remediate CVE-2023-49285?
A fix for CVE-2023-49285 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2023-49285 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-49285

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