CVE-2020-11958

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.7%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

re2c 1.3 has a heap-based buffer overflow in Scanner::fill in parse/scanner.cc via a long lexeme.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100CISA SSVC

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
Severity78% × 45%
Exploitation2% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.7%
EPSS %ILE
76th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

April 21, 2020

Last Modified

November 21, 2024

Advisory Details (5)

Auto-updated Sep 27, 2026
Patch available. Sources: github_commit.
github_commit Patch Available

commit c4603ba5ce22 (skvadrik/re2c)

Patch available: skvadrik/re2c 2.0 (contains commit c4603ba5ce22)

https://github.com/skvadrik/re2c/commit/c4603ba5ce229db83a2a4fb93e6d4b4e3ec3776a
generic

re2c: heap overflow in Scanner::fill (scanner.cc) | agostino's blog

https://blogs.gentoo.org/ago/2020/04/19/re2c-heap-overflow-in-scannerfill-scanner-cc/
generic

oss-security - Re: re2c: heap overflow in Scanner::fill (scanner.cc)

http://www.openwall.com/lists/oss-security/2020/04/21/1
generic

oss-security - re2c: heap overflow in Scanner::fill (scanner.cc)

https://www.openwall.com/lists/oss-security/2020/04/19/1
generic

re2c: Buffer overflow (GLSA 202007-28) — Gentoo security

https://security.gentoo.org/glsa/202007-28

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubunture2c (1.2.1-1ubuntu0.1) @ eoan2026-05-27ubuntu
ubunture2c (1.3-1ubuntu0.1) @ focal2026-05-27ubuntu

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

(18 across 18 ecosystems)
Alpine:v3.11(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.12(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-r1: fixed in 1.3-r1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-2: fixed in 1.3-2
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-2: fixed in 1.3-2
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-2: fixed in 1.3-2
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
re2c—
  • every version up to 1.3-2: fixed in 1.3-2
—

Weakness Classification(1)

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

All Vendor Advisories

(2)

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 5× in last 7d / 26× 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 165 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2020-11958?
CVE-2020-11958 is a high vulnerability published on April 21, 2020. re2c 1.3 has a heap-based buffer overflow in Scanner::fill in parse/scanner.cc via a long lexeme.
When was CVE-2020-11958 disclosed?
CVE-2020-11958 was first published on April 21, 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-2020-11958 actively exploited?
CVE-2020-11958 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.7% probability of exploitation in the next 30 days (76th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-11958?
CVE-2020-11958 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2020-11958?
A fix for CVE-2020-11958 is available: update to the fixed version the vendor names in its advisory.

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