CVE-2023-4911

CRITICALPre-NVD 7.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2023-11-21), indicating real-world exploitation has been confirmed by US federal agencies. the CNA's CVSS baseline 7.8 retained for reference (NVD's own analysis pending). Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, cna:redhat, epss, ghsa
Trending — 5 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 81%CVSS: 7.8Exploit: cisa kev · ssvc active · Metasploit · epss top5pct · epss high · public exploitExposed: 0

A fix is available — apply it.

A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

CVSS v3
7.8
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

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
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
81%
EPSS %ILE
100%
KEV
⚠ Exploited

Published

October 3, 2023

Last Modified

July 14, 2026

Advisory Details (9)

Auto-updated May 12, 2026
🔬 Proof of concept available. Patch available. Sources: redhat.
generic

CVE-2023-4911: Local Privilege Escalation in glibc’s ld.so | Qualys

https://www.qualys.com/cve-2023-4911/
generic🟡 PoC Available
https://www.qualys.com/2023/10/03/cve-2023-4911/looney-tunables-local-privilege-escalation-glibc-ld-so.txt
redhat Patch Available

2238352 – (CVE-2023-4911) CVE-2023-4911 glibc: buffer overflow in ld.so leading to privilege escalation

Affected: Red Hat Enterprise Linux 9.0 Extended Update Support

https://bugzilla.redhat.com/show_bug.cgi?id=2238352
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2023-4911
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2024:0033
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2023:5476
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2023:5455
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2023:5454
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2023:5453

Vendor Advisories for CVE-2023-4911(1)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntunscd (2.37-0ubuntu2.1) @ lunar2026-09-20ubuntu
redhatredhat-virtualization-host-0:4.5.3-202312060823_8.62024-01-03redhat
redhatglibc-0:2.28-189.6.el8_62023-10-05redhat
redhatglibc-0:2.34-60.el9_2.72023-10-05redhat
redhatglibc-0:2.34-28.el9_0.42023-10-05redhat
redhatglibc-0:2.28-225.el8_8.62023-10-05redhat

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
glibc2.31-13 ... 2.31-13+deb11u6 (7 versions)2.31-13+deb11u7—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
glibc2.36-9, 2.36-9+deb12u1, 2.36-9+deb12u22.36-9+deb12u3—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
glibc—2.37-12—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
glibc—2.37-12—

Weakness Classification(2)

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

Additional Vendor Advisories

(6)

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 93× in last 7d / 395× 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 1,480 total refreshes for this CVE.

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

Publicly available exploits

(10 references)

Working exploit code is in the public domain (9 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCjarpex/cve-2023-4911-exploit-optimized
    First seen Jun 29, 2026

    Pure C exploit for CVE-2023-4911 (Looney Tunables) — x86_64 & aarch64 implementations. Multi-processing brute-forcing, dynamic calibration, integrated ELF parser.

    Open source ↗
  • Exploit-DBEDB-52479
    First seen Feb 11, 2026

    glibc 2.38 - Buffer Overflow

    Open source ↗
  • GitHub PoCNishanthAnand21/CVE-2023-4911-PoC
    First seen Jan 20, 2024

    Repository containing a Proof of Concept (PoC) demonstrating the impact of CVE-2023-4911, a vulnerability in glibc's ld.so dynamic loader, exposing risks related to Looney Tunables.

    Open source ↗
  • GitHub PoCpuckiestyle/CVE-2023-4911
    First seen Dec 23, 2023
    Open source ↗
  • GitHub PoCDiego-AltF4/CVE-2023-4911
    First seen Oct 28, 2023

    Proof of concept for CVE-2023-4911 (Looney Tunables) discovered by Qualys Threat Research Unit

    Open source ↗
  • GitHub PoCKernelKrise/CVE-2023-4911
    First seen Oct 25, 2023

    Looney Tunables Local privilege escalation (CVE-2023-4911) workshop

    Open source ↗
  • GitHub PoCchaudharyarjun/LooneyPwner
    First seen Oct 17, 2023

    Exploit tool for CVE-2023-4911, targeting the 'Looney Tunables' glibc vulnerability in various Linux distributions.

    Open source ↗
  • GitHub PoCruycr4ft/CVE-2023-4911
    First seen Oct 11, 2023

    CVE-2023-4911

    Open source ↗
  • GitHub PoChadrian3689/looney-tunables-CVE-2023-4911
    First seen Oct 10, 2023
    Open source ↗
  • GitHub PoCleesh3288/CVE-2023-4911
    First seen Oct 4, 2023

    PoC for CVE-2023-4911

    Open source ↗

Frequently asked(6)

What is CVE-2023-4911?
CVE-2023-4911 is a critical vulnerability published on October 3, 2023. A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBCTUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBCTUNABLES environment variables when launching binaries with SUID permission to execute code…
When was CVE-2023-4911 disclosed?
CVE-2023-4911 was first published in the National Vulnerability Database on October 3, 2023, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-4911 actively exploited?
Yes. CISA added CVE-2023-4911 to the Known Exploited Vulnerabilities catalog on November 21, 2023, affecting GNU GNU C Library. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2023-4911?
CVE-2023-4911 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2023-4911?
CVE-2023-4911 affects GNU GNU C Library. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2023-4911?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-4911, 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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