CVE-2026-1299

MEDIUMNVD 6.06.0—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.0 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 56% 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
6.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.0Exploit: None knownExposed: 0

A fix is available — apply it.

The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".

CVSS v3
6.0
EG Score
6.0(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: 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
Severity60% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

January 23, 2026

Last Modified

June 17, 2026

Advisory Details (10)

Auto-updated Aug 7, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
generic

Mailman 3 [CVE-2026-1299] email BytesGenerator header injection due to unquoted newlines - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/
github_pr

gh-144125: email: verify headers are sound in BytesGenerator

Fix merged in python/cpython PR #144126 on 2026-01-23 — awaiting tagged release

https://github.com/python/cpython/pull/144126
generic

Encode newlines in headers when using ByteGenerator · Issue #144125 · python/cpython · GitHub

https://github.com/python/cpython/issues/144125
github_commit

commit e417f05ad77a (python/cpython)

Fix landed in python/cpython commit e417f05ad77a — awaiting tagged release

https://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831a
github_commit

commit 8cdf6204f4ae (python/cpython)

Fix landed in python/cpython commit 8cdf6204f4ae — awaiting tagged release

https://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36
github_commit

commit 842ce19a0c0b (python/cpython)

Fix landed in python/cpython commit 842ce19a0c0b — awaiting tagged release

https://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4
github_commit

commit 7877fe424415 (python/cpython)

Fix landed in python/cpython commit 7877fe424415 — awaiting tagged release

https://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9
github_commit

commit 0a925ab591c4 (python/cpython)

Fix landed in python/cpython commit 0a925ab591c4 — awaiting tagged release

https://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8
github_commit

commit 052e55e7d447 (python/cpython)

Fix landed in python/cpython commit 052e55e7d447 — awaiting tagged release

https://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413
generic
https://cve.org/CVERecord?id=CVE-2024-6923

Vendor Advisories for CVE-2026-1299(20)

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

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhaiis/vllm-spyre-rhel9:17782445462026-05-12redhat
redhatpython3-12-main-3.12.13-3.hum12026-04-17redhat
redhatrhaiis/vllm-rocm-rhel9:17756802622026-04-17redhat
redhatrhaiis/vllm-cuda-rhel9:17756801922026-04-17redhat
redhatpython3-11-main-3.11.15-4.hum12026-04-17redhat
redhatrhaiis/model-opt-cuda-rhel9:17757498572026-04-17redhat
redhatpython3-14-main-3.14.4-1.hum12026-04-11redhat
redhatpython3-13-main-3.13.13-1.hum12026-04-10redhat
redhatdiscovery/discovery-ui-rhel9:17756759222026-04-09redhat
redhatpython3-0:3.6.8-21.el7_9.42026-04-02redhat
redhatpython3.11-0:3.11.7-1.el9_4.112026-03-31redhat
redhatpython3-0:3.6.8-51.el8_8.132026-03-30redhat
redhatrhceph/rhceph-8-rhel9:17740028672026-03-24redhat
redhatpython3.9-0:3.9.16-1.el9_2.122026-03-23redhat
redhatpython3.9-0:3.9.10-4.el9_0.92026-03-23redhat
redhatpython3-0:3.6.8-39.el8_4.92026-03-23redhat
redhatpython3.11-0:3.11.2-2.el9_2.102026-03-23redhat
redhatpython3.12-0:3.12.9-2.el10_0.72026-03-23redhat
redhatpython3-0:3.6.8-24.el8_2.62026-03-23redhat
redhatpython3.9-0:3.9.18-3.el9_4.112026-03-23redhat
redhatpython3.12-0:3.12.1-4.el9_4.112026-03-23redhat
redhatpython3.9-0:3.9.21-2.el9_6.42026-03-23redhat
redhatpython3-0:3.6.8-47.el8_6.112026-03-23redhat
redhatpython3.11-0:3.11.2-2.el8_8.82026-03-19redhat
redhatrhui5/rhua-rhel9:17736701372026-03-18redhat
redhatpython3.12-0:3.12.12-3.el10_1.12026-03-17redhat
redhatpython3.12-0:3.12.9-1.el9_6.62026-03-17redhat
redhatpython3.11-0:3.11.13-5.el8_102026-03-12redhat
redhatpython3.12-0:3.12.12-3.el8_102026-03-12redhat
redhatpython3.12-0:3.12.12-4.el9_7.12026-03-10redhat

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 4 ecosystems)
Debian:14(3)
PackageVulnerable rangeFixed inDependents
pypy37.3.19+dfsg-2, 7.3.20+dfsg-1, 7.3.20+dfsg-2, 7.3.20+dfsg-3, 7.3.20+dfsg-47.3.21+dfsg-1—
python3.133.13.11-1 ... 3.13.9-1 (6 versions)3.13.12-1—
python3.143.14.0-1 ... 3.14.2-1 (14 versions)3.14.3-1—
Debian:11(2)
PackageVulnerable rangeFixed inDependents
pypy37.3.10+dfsg-1 ... 7.3.9+dfsg-5 (53 versions)——
python3.93.9.2-1, 3.9.2-1+deb11u1, 3.9.2-1+deb11u2, 3.9.2-1+deb11u3, 3.9.2-1+deb11u43.9.2-1+deb11u5—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
pypy37.3.11+dfsg-2 ... 7.3.23+dfsg-1 (29 versions)——
python3.113.11.2-6 ... 3.11.2-6+deb12u6 (7 versions)3.11.2-6+deb12u7—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
pypy37.3.19+dfsg-2 ... 7.3.23+dfsg-1 (11 versions)——
python3.133.13.5-23.13.5-2+deb13u1—

Weakness Classification(1)

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

Additional Vendor Advisories

(13)

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 / 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.

Showing the most recent 100 of 165 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-1299?
CVE-2026-1299 is a medium vulnerability published on January 23, 2026. The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding…
When was CVE-2026-1299 disclosed?
CVE-2026-1299 was first published in the National Vulnerability Database on January 23, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-1299 actively exploited?
CVE-2026-1299 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 57.1% of all scored CVEs.
What is the CVSS score of CVE-2026-1299?
CVE-2026-1299 has a CVSS v3 base score of 6.0 (NVD).
How do I remediate CVE-2026-1299?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-1299, 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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