CVE-2026-28388

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-04-08. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

Issue summary: When a delta CRL that contains a Delta CRL Indicator extension is processed a NULL pointer dereference might happen if the required CRL Number extension is missing.

Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application.

When CRL processing and delta CRL processing is enabled during X.509 certificate verification, the delta CRL processing does not check whether the CRL Number extension is NULL before dereferencing it. When a malformed delta CRL file is being processed, this parameter can be NULL, causing a NULL pointer dereference.

Exploiting this issue requires the X509_V_FLAG_USE_DELTAS flag to be enabled in the verification context, the certificate being verified to contain a freshestCRL extension or the base CRL to have the EXFLAG_FRESHEST flag set, and an attacker to provide a malformed CRL to an application that processes it.

The vulnerability is limited to Denial of Service and cannot be escalated to achieve code execution or memory disclosure. For that reason the issue was assessed as Low severity according to our Security Policy.

The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
57%
KEV
Not listed

Published

April 7, 2026

Last Modified

July 24, 2026

Advisory Details (8)

Auto-updated Jul 25, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

SSA-265688

https://cert-portal.siemens.com/productcert/html/ssa-265688.html
generic

SSA-032379

https://cert-portal.siemens.com/productcert/html/ssa-032379.html
generic
https://openssl-library.org/news/secadv/20260407.txt
github_commit

commit d3a901e8d9f0 (openssl/openssl)

Fix landed in openssl/openssl commit d3a901e8d9f0 — awaiting tagged release

https://github.com/openssl/openssl/commit/d3a901e8d9f021f3e67d6cfbc12e768129862726
github_commit

commit a9d187dd1000 (openssl/openssl)

Fix landed in openssl/openssl commit a9d187dd1000 — awaiting tagged release

https://github.com/openssl/openssl/commit/a9d187dd1000130100fa7ab915f8513532cb3bb8
github_commit

commit 602542f2c0c2 (openssl/openssl)

Fix landed in openssl/openssl commit 602542f2c0c2 — awaiting tagged release

https://github.com/openssl/openssl/commit/602542f2c0c2d5edb47128f93eac10b62aeeefb3
github_commit

commit 5a0b4930779c (openssl/openssl)

Fix landed in openssl/openssl commit 5a0b4930779c — awaiting tagged release

https://github.com/openssl/openssl/commit/5a0b4930779cd2408880979db765db919da55139
github_commit

commit 59c3b3158553 (openssl/openssl)

Fix landed in openssl/openssl commit 59c3b3158553 — awaiting tagged release

https://github.com/openssl/openssl/commit/59c3b3158553ab53275bbbccca5cb305d591cf2e

Vendor Advisories for CVE-2026-28388(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuopenssl (3.0.2-0ubuntu1.23) @ jammy2026-07-26ubuntu
ubuntuopenssl (1.0.2g-1ubuntu4.20+esm15) @ xenial2026-07-26ubuntu
redhatopenssl-main-3.5.6-0.1.hum12026-04-09redhat

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

(9 across 9 ecosystems)
Alpine:v3.20(1)
PackageVulnerable rangeFixed inDependents
openssl—3.3.7-r0—
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
openssl—3.3.7-r0—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
openssl—3.5.6-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
openssl—3.5.6-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
openssl—3.5.6-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
openssl1.1.1k-1 ... 1.1.1w-0~deb11u1 (22 versions)1.1.1w-0+deb11u7—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
openssl3.0.10-1 ... 3.0.9-1 (20 versions)3.0.19-1~deb12u2—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
openssl3.5.1-1 ... 3.5.5-1~deb13u1 (8 versions)3.5.5-1~deb13u2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
openssl3.5.1-1 ... 3.6.1-3 (20 versions)3.6.2-1—

Weakness Classification(1)

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 5× in last 7d / 32× 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 232 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-28388?
CVE-2026-28388 is a high vulnerability published on April 7, 2026. Issue summary: When a delta CRL that contains a Delta CRL Indicator extension is processed a NULL pointer dereference might happen if the required CRL Number extension is missing. Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application.…
When was CVE-2026-28388 disclosed?
CVE-2026-28388 was first published in the National Vulnerability Database on April 7, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28388 actively exploited?
CVE-2026-28388 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 42.8% of all scored CVEs.
What is the CVSS score of CVE-2026-28388?
CVE-2026-28388 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-28388?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28388, 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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