CURL-CVE-2026-87864

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Source
https://curl.se/docs/CVE-2026-87864.html
Import Source
https://curl.se/docs/CURL-CVE-2026-87864.json
JSON Data
https://api.osv.dev/v1/vulns/CURL-CVE-2026-87864
Aliases
  • CVE-2026-87864
Published
2026-10-14T08:00:00Z
Modified
2026-10-14T19:02:58Z
Summary
IMAP APPEND plus CRLF conversion command injection
Details

Enabling CURLOPT_CRLF causes curl to advertise the raw input byte count in the IMAP APPEND {N} literal while transmitting line-ending expanded data. The server reads only $N$ bytes for the payload, causing the remaining overflow bytes to be interpreted and executed as pipelined IMAP commands within the authenticated session.

Database specific 
{
    "CWE":  {
        "desc":  "Improper Handling of Length Parameter Inconsistency",
        "id":  "CWE-130"
    },
    "URL":  "https://curl.se/docs/CVE-2026-87864.json",
    "affects":  "both",
    "issue":  "https://hackerone.com/reports/3972403",
    "last_affected":  "8.21.0",
    "package":  "curl",
    "severity":  "Low",
    "www":  "https://curl.se/docs/CVE-2026-87864.html"
}
Credits
    • Stanislav Fort (Aisle Research) - FINDER
    • Stefan Eissing - REMEDIATION_DEVELOPER

Affected packages

Git / github.com/curl/curl.git

Affected ranges

Type
SEMVER
Events
Introduced
7.30.0
Fixed
8.14.3
Introduced
8.15.0
Fixed
8.16.2
Introduced
8.17.0
Fixed
8.20.2
Introduced
8.21.0
Fixed
8.22.0
Type
GIT
Repo
https://github.com/curl/curl.git
Events
Introduced
f8c8c76d39ac2fa825481ba42ab2247cd122f963
Fixed
3b547de301342b347fb3c6ea6ae7979070793a66

Affected versions

7.*
7.30.0
7.31.0
7.32.0
7.33.0
7.34.0
7.35.0
7.36.0
7.37.0
7.37.1
7.38.0
7.39.0
7.40.0
7.41.0
7.42.0
7.42.1
7.43.0
7.44.0
7.45.0
7.46.0
7.47.0
7.47.1
7.48.0
7.49.0
7.49.1
7.50.0
7.50.1
7.50.2
7.50.3
7.51.0
7.52.0
7.52.1
7.53.0
7.53.1
7.54.0
7.54.1
7.55.0
7.55.1
7.56.0
7.56.1
7.57.0
7.58.0
7.59.0
7.60.0
7.61.0
7.61.1
7.62.0
7.63.0
7.64.0
7.64.1
7.65.0
7.65.1
7.65.2
7.65.3
7.66.0
7.67.0
7.68.0
7.69.0
7.69.1
7.70.0
7.71.0
7.71.1
7.72.0
7.73.0
7.74.0
7.75.0
7.76.0
7.76.1
7.77.0
7.78.0
7.79.0
7.79.1
7.80.0
7.81.0
7.82.0
7.83.0
7.83.1
7.84.0
7.85.0
7.86.0
7.87.0
7.88.0
7.88.1
8.*
8.0.0
8.0.1
8.1.0
8.1.1
8.1.2
8.10.0
8.10.1
8.11.0
8.11.1
8.12.0
8.12.1
8.13.0
8.14.0
8.14.1
8.15.0
8.16.0
8.17.0
8.18.0
8.19.0
8.2.0
8.2.1
8.20.0
8.21.0
8.3.0
8.4.0
8.5.0
8.6.0
8.7.0
8.7.1
8.8.0
8.9.0
8.9.1
Other
curl-7_30_0
curl-7_31_0
curl-7_32_0
curl-7_33_0
curl-7_34_0
curl-7_35_0
curl-7_36_0
curl-7_37_0
curl-7_37_1
curl-7_38_0
curl-7_39_0
curl-7_40_0
curl-7_41_0
curl-7_42_0
curl-7_42_1
curl-7_43_0
curl-7_44_0
curl-7_45_0
curl-7_46_0
curl-7_47_0
curl-7_47_1
curl-7_48_0
curl-7_49_0
curl-7_49_1
curl-7_50_0
curl-7_50_1
curl-7_50_2
curl-7_50_3
curl-7_51_0
curl-7_52_0
curl-7_52_1
curl-7_53_0
curl-7_53_1
curl-7_54_0
curl-7_54_1
curl-7_55_0
curl-7_55_1
curl-7_56_0
curl-7_56_1
curl-7_57_0
curl-7_58_0
curl-7_59_0
curl-7_60_0
curl-7_61_0
curl-7_61_1
curl-7_62_0
curl-7_63_0
curl-7_64_0
curl-7_64_1
curl-7_65_0
curl-7_65_1
curl-7_65_2
curl-7_65_3
curl-7_66_0
curl-7_67_0
curl-7_68_0
curl-7_69_0
curl-7_69_1
curl-7_70_0
curl-7_71_0
curl-7_71_1
curl-7_72_0
curl-7_73_0
curl-7_74_0
curl-7_75_0
curl-7_76_0
curl-7_76_1
curl-7_77_0
curl-7_78_0
curl-7_79_0
curl-7_79_1
curl-7_80_0
curl-7_81_0
curl-7_82_0
curl-7_83_0
curl-7_83_1
curl-7_84_0
curl-7_85_0
curl-7_86_0
curl-7_87_0
curl-7_88_0
curl-7_88_1
curl-8_0_0
curl-8_0_1
curl-8_10_0
curl-8_10_1
curl-8_11_0
curl-8_11_1
curl-8_12_0
curl-8_12_1
curl-8_13_0
curl-8_14_0
curl-8_14_1
curl-8_15_0
curl-8_16_0
curl-8_17_0
curl-8_18_0
curl-8_19_0
curl-8_1_0
curl-8_1_1
curl-8_1_2
curl-8_20_0
curl-8_21_0
curl-8_2_0
curl-8_2_1
curl-8_3_0
curl-8_4_0
curl-8_5_0
curl-8_6_0
curl-8_7_0
curl-8_7_1
curl-8_8_0
curl-8_9_0
curl-8_9_1
rc-8_18_0-1
rc-8_18_0-2
rc-8_18_0-3
rc-8_19_0-1
rc-8_19_0-2
rc-8_19_0-3
rc-8_20_0-1
rc-8_20_0-2
rc-8_20_0-3
rc-8_21_0-1
rc-8_21_0-2
rc-8_21_0-3
rc-8_22_0-1
rc-8_22_0-2
rc-8_22_0-3
tiny-curl-7_72_0
tiny-curl-8_4_0

Database specific

source 
"https://curl.se/docs/CURL-CVE-2026-87864.json"
vanir_signatures 
[
    {
        "deprecated":  false,
        "digest":  {
            "function_hash":  "271163736960417285140970839678364115519",
            "length":  2049
        },
        "id":  "CURL-CVE-2026-87864-0ce8cfa2",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/curl/curl.git/commit/3b547de301342b347fb3c6ea6ae7979070793a66",
        "target":  {
            "file":  "lib/imap.c",
            "function":  "imap_perform_append"
        }
    },
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "251391810045803685832643111882952219983",
                "230272450495413905076510337395308289975",
                "279345524937848122541175804955803927206",
                "326579516450104158312078249796725653019",
                "6314725441832225559310330025237115345",
                "114921374853254453887647134154033142821",
                "21107455571070083965206735011929559656",
                "181508033716914528430102015631184913514",
                "550900563960819447413324627059592860"
            ],
            "threshold":  0.9
        },
        "id":  "CURL-CVE-2026-87864-1bd163f9",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/curl/curl.git/commit/3b547de301342b347fb3c6ea6ae7979070793a66",
        "target":  {
            "file":  "lib/imap.c"
        }
    }
]
vanir_signatures_modified 
"2026-10-14T19:02:58Z"